diff --git a/exercises/clippy/clippy1.rs b/exercises/clippy/clippy1.rs
index bad46891..88e6ecc2 100644
--- a/exercises/clippy/clippy1.rs
+++ b/exercises/clippy/clippy1.rs
@@ -6,15 +6,15 @@
 // check clippy's suggestions from the output to solve the exercise.
 // Execute `rustlings hint clippy1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM  DONE
 
 use std::f32;
 
 fn main() {
-    let pi = 3.14f32;
+    const  PI:f32 = std::f32::consts::PI;
     let radius = 5.00f32;
 
-    let area = pi * f32::powi(radius, 2);
+    let area = PI * f32::powi(radius, 2);
 
     println!(
         "The area of a circle with radius {:.2} is {:.5}!",
diff --git a/exercises/clippy/clippy2.rs b/exercises/clippy/clippy2.rs
index dac40dbe..2c3ebc1a 100644
--- a/exercises/clippy/clippy2.rs
+++ b/exercises/clippy/clippy2.rs
@@ -1,12 +1,12 @@
 // clippy2.rs
 // Execute `rustlings hint clippy2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 fn main() {
     let mut res = 42;
     let option = Some(12);
-    for x in option {
+    if let Some(x) = option {
         res += x;
     }
     println!("{}", res);
diff --git a/exercises/clippy/clippy3.rs b/exercises/clippy/clippy3.rs
index b0159ebe..012b9209 100644
--- a/exercises/clippy/clippy3.rs
+++ b/exercises/clippy/clippy3.rs
@@ -1,28 +1,29 @@
 // clippy3.rs
 // Here's a couple more easy Clippy fixes, so you can see its utility.
 
-// I AM NOT DONE
+// I AM DONE
 
 #[allow(unused_variables, unused_assignments)]
 fn main() {
     let my_option: Option<()> = None;
-    if my_option.is_none() {
-        my_option.unwrap();
-    }
+    // if my_option.is_none() {
+    //     my_option.unwrap();
+    // }
 
     let my_arr = &[
-        -1, -2, -3
+        -1, -2, -3,
         -4, -5, -6
     ];
     println!("My array! Here it is: {:?}", my_arr);
 
-    let my_empty_vec = vec![1, 2, 3, 4, 5].resize(0, 5);
+    let my_empty_vec = vec![0;5];
     println!("This Vec is empty, see? {:?}", my_empty_vec);
 
     let mut value_a = 45;
     let mut value_b = 66;
     // Let's swap these two!
-    value_a = value_b;
-    value_b = value_a;
+    // value_a = value_b;
+    // value_b = value_a;
+    std::mem::swap(&mut value_a, &mut value_b);
     println!("value a: {}; value b: {}", value_a, value_b);
 }
diff --git a/exercises/conversions/from_into.rs b/exercises/conversions/from_into.rs
index 6c272c3b..9e8a529b 100644
--- a/exercises/conversions/from_into.rs
+++ b/exercises/conversions/from_into.rs
@@ -39,6 +39,15 @@ impl Default for Person {
 
 impl From<&str> for Person {
     fn from(s: &str) -> Person {
+        if s.len() == 0 {
+            Default::default()
+        } else {
+            let tmp: Vec<&str> = s.split(',').collect();
+            Person {
+                name: String::from(tmp[0]),
+                age: tmp[1].parse::<usize>().unwrap(),
+            }
+        }
     }
 }
 
diff --git a/exercises/conversions/using_as.rs b/exercises/conversions/using_as.rs
index 8c9b7113..2ab39c02 100644
--- a/exercises/conversions/using_as.rs
+++ b/exercises/conversions/using_as.rs
@@ -6,11 +6,11 @@
 // and returns the proper type.
 // Execute `rustlings hint using_as` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 fn average(values: &[f64]) -> f64 {
     let total = values.iter().sum::<f64>();
-    total / values.len()
+    total / values.len() as f64
 }
 
 fn main() {
diff --git a/exercises/enums/enums1.rs b/exercises/enums/enums1.rs
index 511ba740..e78564d3 100644
--- a/exercises/enums/enums1.rs
+++ b/exercises/enums/enums1.rs
@@ -1,11 +1,15 @@
 // enums1.rs
 // No hints this time! ;)
 
-// I AM NOT DONE
+// I AM  DONE
 
 #[derive(Debug)]
 enum Message {
     // TODO: define a few types of messages as used below
+    Quit,
+    Echo,
+    Move,
+    ChangeColor
 }
 
 fn main() {
diff --git a/exercises/enums/enums2.rs b/exercises/enums/enums2.rs
index 18479f87..e6dfae4e 100644
--- a/exercises/enums/enums2.rs
+++ b/exercises/enums/enums2.rs
@@ -1,11 +1,15 @@
 // enums2.rs
 // Execute `rustlings hint enums2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 #[derive(Debug)]
 enum Message {
     // TODO: define the different variants used below
+    Quit,
+    Echo (String),
+    Move { x: i32, y: i32},
+    ChangeColor (i32, i32, i32),
 }
 
 impl Message {
diff --git a/exercises/enums/enums3.rs b/exercises/enums/enums3.rs
index 55acf6bc..b072cc1c 100644
--- a/exercises/enums/enums3.rs
+++ b/exercises/enums/enums3.rs
@@ -2,10 +2,14 @@
 // Address all the TODOs to make the tests pass!
 // Execute `rustlings hint enums3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 enum Message {
     // TODO: implement the message variant types based on their usage below
+    Quit,
+    Echo (String),
+    Move (Point),
+    ChangeColor ((u8, u8, u8)),
 }
 
 struct Point {
@@ -38,6 +42,12 @@ impl State {
 
     fn process(&mut self, message: Message) {
         // TODO: create a match expression to process the different message variants
+        match message {
+            Message::Echo(val) => self.echo(val),
+            Message::Quit => self.quit(),
+            Message::Move(val) => self.move_position(val),
+            Message::ChangeColor((a,b,c)) => self.change_color((a,b,c)),
+        }
     }
 }
 
diff --git a/exercises/error_handling/errors1.rs b/exercises/error_handling/errors1.rs
index bcee9723..e8ff9b6f 100644
--- a/exercises/error_handling/errors1.rs
+++ b/exercises/error_handling/errors1.rs
@@ -5,14 +5,14 @@
 // construct to `Option` that can be used to express error conditions. Let's use it!
 // Execute `rustlings hint errors1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
-pub fn generate_nametag_text(name: String) -> Option<String> {
+pub fn generate_nametag_text(name: String) -> Result<String, String> {
     if name.is_empty() {
         // Empty names aren't allowed.
-        None
+       Err("`name` was empty; it must be nonempty.".into())
     } else {
-        Some(format!("Hi! My name is {}", name))
+       Ok(format!("Hi! My name is {}", name))
     }
 }
 
diff --git a/exercises/error_handling/errors2.rs b/exercises/error_handling/errors2.rs
index 1cd8fc66..d1f7407f 100644
--- a/exercises/error_handling/errors2.rs
+++ b/exercises/error_handling/errors2.rs
@@ -17,15 +17,14 @@
 // one is a lot shorter!
 // Execute `rustlings hint errors2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 use std::num::ParseIntError;
 
 pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
     let processing_fee = 1;
     let cost_per_item = 5;
-    let qty = item_quantity.parse::<i32>();
-
+    let qty = item_quantity.parse::<i32>()?;
     Ok(qty * cost_per_item + processing_fee)
 }
 
diff --git a/exercises/error_handling/errors3.rs b/exercises/error_handling/errors3.rs
index a2d2d190..bee39d17 100644
--- a/exercises/error_handling/errors3.rs
+++ b/exercises/error_handling/errors3.rs
@@ -4,22 +4,23 @@
 // Why not? What should we do to fix it?
 // Execute `rustlings hint errors3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 use std::num::ParseIntError;
 
-fn main() {
+fn main() -> Result<(), ParseIntError> {
     let mut tokens = 100;
     let pretend_user_input = "8";
 
     let cost = total_cost(pretend_user_input)?;
-
+    println!("cost is {}", cost);
     if cost > tokens {
         println!("You can't afford that many!");
     } else {
         tokens -= cost;
         println!("You now have {} tokens.", tokens);
     }
+    Ok(())
 }
 
 pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
diff --git a/exercises/error_handling/errors4.rs b/exercises/error_handling/errors4.rs
index 0efe8ccd..e40b4b50 100644
--- a/exercises/error_handling/errors4.rs
+++ b/exercises/error_handling/errors4.rs
@@ -1,7 +1,7 @@
 // errors4.rs
 // Execute `rustlings hint errors4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 #[derive(PartialEq, Debug)]
 struct PositiveNonzeroInteger(u64);
@@ -15,7 +15,11 @@ enum CreationError {
 impl PositiveNonzeroInteger {
     fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
         // Hmm...? Why is this only returning an Ok value?
-        Ok(PositiveNonzeroInteger(value as u64))
+        match value { 
+            x if x > 0 => Ok(PositiveNonzeroInteger(value as u64)),
+            0 => Err(CreationError::Zero),
+            _ => Err(CreationError::Negative),
+        }
     }
 }
 
diff --git a/exercises/error_handling/errors5.rs b/exercises/error_handling/errors5.rs
index 2ba8f903..3fab123b 100644
--- a/exercises/error_handling/errors5.rs
+++ b/exercises/error_handling/errors5.rs
@@ -16,14 +16,14 @@
 
 // Execute `rustlings hint errors5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 use std::error;
 use std::fmt;
 use std::num::ParseIntError;
 
 // TODO: update the return type of `main()` to make this compile.
-fn main() -> Result<(), Box<dyn ???>> {
+fn main() -> Result<(), Box<dyn error::Error>> {
     let pretend_user_input = "42";
     let x: i64 = pretend_user_input.parse()?;
     println!("output={:?}", PositiveNonzeroInteger::new(x)?);
diff --git a/exercises/error_handling/errors6.rs b/exercises/error_handling/errors6.rs
index 1306fb03..4daeecfe 100644
--- a/exercises/error_handling/errors6.rs
+++ b/exercises/error_handling/errors6.rs
@@ -8,7 +8,7 @@
 
 // Execute `rustlings hint errors6` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 use std::num::ParseIntError;
 
@@ -24,7 +24,9 @@ impl ParsePosNonzeroError {
         ParsePosNonzeroError::Creation(err)
     }
     // TODO: add another error conversion function here.
-    // fn from_parseint...
+    fn from_parseint(err: ParseIntError) -> ParsePosNonzeroError {
+        ParsePosNonzeroError::ParseInt(err)
+    }
 }
 
 fn parse_pos_nonzero(s: &str)
@@ -32,7 +34,12 @@ fn parse_pos_nonzero(s: &str)
 {
     // TODO: change this to return an appropriate error instead of panicking
     // when `parse()` returns an error.
-    let x: i64 = s.parse().unwrap();
+    let relt: Result<i64, ParsePosNonzeroError> = s.parse().map_err(ParsePosNonzeroError::from_parseint);
+    let mut x: i64 = 0;
+    match relt {
+        Ok(val) => x = val,
+        Err(error) => return Err(error),
+    };
     PositiveNonzeroInteger::new(x)
         .map_err(ParsePosNonzeroError::from_creation)
 }
diff --git a/exercises/functions/functions1.rs b/exercises/functions/functions1.rs
index 03d8af70..c0688a78 100644
--- a/exercises/functions/functions1.rs
+++ b/exercises/functions/functions1.rs
@@ -1,7 +1,10 @@
 // functions1.rs
 // Execute `rustlings hint functions1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT DON
+fn call_me() {
+    println!("haha {}","NT");
+}
 
 fn main() {
     call_me();
diff --git a/exercises/functions/functions2.rs b/exercises/functions/functions2.rs
index 7d40a578..9187ddef 100644
--- a/exercises/functions/functions2.rs
+++ b/exercises/functions/functions2.rs
@@ -1,13 +1,13 @@
 // functions2.rs
 // Execute `rustlings hint functions2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT DON
 
 fn main() {
     call_me(3);
 }
 
-fn call_me(num:) {
+fn call_me(num:i32) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }
diff --git a/exercises/functions/functions3.rs b/exercises/functions/functions3.rs
index 3b9e585b..fc8d992c 100644
--- a/exercises/functions/functions3.rs
+++ b/exercises/functions/functions3.rs
@@ -1,10 +1,10 @@
 // functions3.rs
 // Execute `rustlings hint functions3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT DON
 
 fn main() {
-    call_me();
+    call_me(3);
 }
 
 fn call_me(num: u32) {
diff --git a/exercises/functions/functions4.rs b/exercises/functions/functions4.rs
index 65d5be4f..d712c5b8 100644
--- a/exercises/functions/functions4.rs
+++ b/exercises/functions/functions4.rs
@@ -7,14 +7,14 @@
 // in the signatures for now. If anything, this is a good way to peek ahead
 // to future exercises!)
 
-// I AM NOT DONE
+// I AM NOT DON
 
 fn main() {
     let original_price = 51;
     println!("Your sale price is {}", sale_price(original_price));
 }
 
-fn sale_price(price: i32) -> {
+fn sale_price(price: i32) -> i32{
     if is_even(price) {
         price - 10
     } else {
diff --git a/exercises/functions/functions5.rs b/exercises/functions/functions5.rs
index 5d762961..0dea2060 100644
--- a/exercises/functions/functions5.rs
+++ b/exercises/functions/functions5.rs
@@ -1,7 +1,7 @@
 // functions5.rs
 // Execute `rustlings hint functions5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT 
 
 fn main() {
     let answer = square(3);
@@ -9,5 +9,5 @@ fn main() {
 }
 
 fn square(num: i32) -> i32 {
-    num * num;
+    return num * num;
 }
diff --git a/exercises/generics/generics1.rs b/exercises/generics/generics1.rs
index 4c34ae47..c41f3275 100644
--- a/exercises/generics/generics1.rs
+++ b/exercises/generics/generics1.rs
@@ -3,9 +3,9 @@
 
 // Execute `rustlings hint generics1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 fn main() {
-    let mut shopping_list: Vec<?> = Vec::new();
+    let mut shopping_list: Vec<&str> = Vec::new();
     shopping_list.push("milk");
 }
diff --git a/exercises/generics/generics2.rs b/exercises/generics/generics2.rs
index aedbd55c..dbc20f03 100644
--- a/exercises/generics/generics2.rs
+++ b/exercises/generics/generics2.rs
@@ -3,14 +3,14 @@
 
 // Execute `rustlings hint generics2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
-struct Wrapper {
-    value: u32,
+struct Wrapper<T> {
+    value: T,
 }
 
-impl Wrapper {
-    pub fn new(value: u32) -> Self {
+impl<T> Wrapper<T> {
+    pub fn new(value: T) -> Self {
         Wrapper { value }
     }
 }
diff --git a/exercises/hashmaps/hashmaps1.rs b/exercises/hashmaps/hashmaps1.rs
index fd8dd2f8..a07359b6 100644
--- a/exercises/hashmaps/hashmaps1.rs
+++ b/exercises/hashmaps/hashmaps1.rs
@@ -10,12 +10,15 @@
 //
 // Execute `rustlings hint hashmaps1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 use std::collections::HashMap;
 
 fn fruit_basket() -> HashMap<String, u32> {
-    let mut basket = // TODO: declare your hash map here.
+    let mut basket = HashMap::from([
+        ("apple".to_string(), 1),
+        ("juice".to_string(), 7)
+    ]); // TODO: declare your hash map here.
 
     // Two bananas are already given for you :)
     basket.insert(String::from("banana"), 2);
diff --git a/exercises/hashmaps/hashmaps2.rs b/exercises/hashmaps/hashmaps2.rs
index 454b3e1d..73eeec01 100644
--- a/exercises/hashmaps/hashmaps2.rs
+++ b/exercises/hashmaps/hashmaps2.rs
@@ -11,7 +11,7 @@
 //
 // Execute `rustlings hint hashmaps2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 use std::collections::HashMap;
 
@@ -37,6 +37,12 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
         // TODO: Put new fruits if not already present. Note that you
         // are not allowed to put any type of fruit that's already
         // present!
+        match basket.get(&fruit) {
+            Some(a) => continue ,
+            None => {
+                basket.insert(fruit, 8);
+            }
+        }
     }
 }
 
diff --git a/exercises/hashmaps/hashmaps3.rs b/exercises/hashmaps/hashmaps3.rs
index 18dd44c9..0120bef0 100644
--- a/exercises/hashmaps/hashmaps3.rs
+++ b/exercises/hashmaps/hashmaps3.rs
@@ -14,11 +14,12 @@
 
 // Execute `rustlings hint hashmaps3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 use std::collections::HashMap;
 
 // A structure to store team name and its goal details.
+// #[derive(PartialEq)]
 struct Team {
     name: String,
     goals_scored: u8,
@@ -40,6 +41,31 @@ fn build_scores_table(results: String) -> HashMap<String, Team> {
         // will be number of goals conceded from team_2, and similarly
         // goals scored by team_2 will be the number of goals conceded by
         // team_1.
+        if scores.contains_key(&team_1_name) == false {
+            scores.insert(team_1_name.clone(), Team {
+                name: team_1_name.clone(),
+                goals_scored: 0,
+                goals_conceded: 0
+            });
+        }
+
+        if scores.contains_key(&team_2_name) == false {
+            scores.insert(team_2_name.clone(), Team {
+                name: team_2_name.clone(),
+                goals_scored: 0,
+                goals_conceded: 0
+            });
+        }
+
+        // add tables
+        let mut v1 = scores.get_mut(&team_1_name).unwrap();
+        v1.goals_scored += team_1_score;
+        v1.goals_conceded += team_2_score;
+
+        let mut v2 = scores.get_mut(&team_2_name).unwrap();
+        v2.goals_scored += team_2_score;
+        v2.goals_conceded += team_1_score;
+
     }
     scores
 }
diff --git a/exercises/if/if1.rs b/exercises/if/if1.rs
index 587e03f8..be472f6c 100644
--- a/exercises/if/if1.rs
+++ b/exercises/if/if1.rs
@@ -1,13 +1,18 @@
 // if1.rs
 // Execute `rustlings hint if1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT DO
 
 pub fn bigger(a: i32, b: i32) -> i32 {
     // Complete this function to return the bigger number!
     // Do not use:
     // - another function call
     // - additional variables
+    if a > b {
+        a
+    } else {
+        b
+    }
 }
 
 // Don't mind this for now :)
diff --git a/exercises/if/if2.rs b/exercises/if/if2.rs
index effddbb6..a4be725e 100644
--- a/exercises/if/if2.rs
+++ b/exercises/if/if2.rs
@@ -4,13 +4,15 @@
 // Step 2: Get the bar_for_fuzz and default_to_baz tests passing!
 // Execute `rustlings hint if2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT 
 
 pub fn foo_if_fizz(fizzish: &str) -> &str {
     if fizzish == "fizz" {
         "foo"
+    } else if fizzish == "fuzz" {
+        "bar"
     } else {
-        1
+        "baz"
     }
 }
 
diff --git a/exercises/intro/intro1.rs b/exercises/intro/intro1.rs
index 45c5acba..1f2e8b10 100644
--- a/exercises/intro/intro1.rs
+++ b/exercises/intro/intro1.rs
@@ -9,7 +9,7 @@
 // when you change one of the lines below! Try adding a `println!` line, or try changing
 // what it outputs in your terminal. Try removing a semicolon and see what happens!
 
-// I AM NOT DONE
+
 
 fn main() {
     println!("Hello and");
diff --git a/exercises/intro/intro2.rs b/exercises/intro/intro2.rs
index efc1af20..04b4fcd1 100644
--- a/exercises/intro/intro2.rs
+++ b/exercises/intro/intro2.rs
@@ -2,8 +2,7 @@
 // Make the code print a greeting to the world.
 // Execute `rustlings hint intro2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
-    println!("Hello {}!");
+    println!("Hello {}!", "world!");
 }
diff --git a/exercises/lifetimes/lifetimes1.rs b/exercises/lifetimes/lifetimes1.rs
index 0236470d..47c85114 100644
--- a/exercises/lifetimes/lifetimes1.rs
+++ b/exercises/lifetimes/lifetimes1.rs
@@ -7,13 +7,21 @@
 //
 // Execute `rustlings hint lifetimes1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
-fn longest(x: &str, y: &str) -> &str {
+// fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
+//     if x.len() > y.len() {
+//         x
+//     } else {
+//         y
+//     }
+// }
+
+fn longest(x: &str, y: &str) -> String {
     if x.len() > y.len() {
-        x
+        x.to_string()
     } else {
-        y
+        y.to_string()
     }
 }
 
diff --git a/exercises/lifetimes/lifetimes2.rs b/exercises/lifetimes/lifetimes2.rs
index b48feabc..88b0bb7b 100644
--- a/exercises/lifetimes/lifetimes2.rs
+++ b/exercises/lifetimes/lifetimes2.rs
@@ -6,7 +6,7 @@
 //
 // Execute `rustlings hint lifetimes2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
     if x.len() > y.len() {
@@ -19,8 +19,9 @@ fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
 fn main() {
     let string1 = String::from("long string is long");
     let result;
+    let string2 = String::from("xyz");
     {
-        let string2 = String::from("xyz");
+        
         result = longest(string1.as_str(), string2.as_str());
     }
     println!("The longest string is '{}'", result);
diff --git a/exercises/lifetimes/lifetimes3.rs b/exercises/lifetimes/lifetimes3.rs
index ea483708..8376a70d 100644
--- a/exercises/lifetimes/lifetimes3.rs
+++ b/exercises/lifetimes/lifetimes3.rs
@@ -4,11 +4,11 @@
 //
 // Execute `rustlings hint lifetimes3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
-struct Book {
-    author: &str,
-    title: &str,
+struct Book<'a> {
+    author: &'a str,
+    title: &'a str,
 }
 
 fn main() {
diff --git a/exercises/macros/macros1.rs b/exercises/macros/macros1.rs
index 634d0a70..103f49f0 100644
--- a/exercises/macros/macros1.rs
+++ b/exercises/macros/macros1.rs
@@ -1,7 +1,7 @@
 // macros1.rs
 // Execute `rustlings hint macros1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 macro_rules! my_macro {
     () => {
@@ -10,5 +10,5 @@ macro_rules! my_macro {
 }
 
 fn main() {
-    my_macro();
+    my_macro!();
 }
diff --git a/exercises/macros/macros2.rs b/exercises/macros/macros2.rs
index f6092cab..5bf68153 100644
--- a/exercises/macros/macros2.rs
+++ b/exercises/macros/macros2.rs
@@ -1,14 +1,15 @@
 // macros2.rs
 // Execute `rustlings hint macros2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
-fn main() {
-    my_macro!();
-}
 
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
     };
 }
+
+fn main() {
+    my_macro!();
+}
diff --git a/exercises/macros/macros3.rs b/exercises/macros/macros3.rs
index 106f1c6d..7920083f 100644
--- a/exercises/macros/macros3.rs
+++ b/exercises/macros/macros3.rs
@@ -2,16 +2,24 @@
 // Make me compile, without taking the macro out of the module!
 // Execute `rustlings hint macros3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
-mod macros {
+// #[macro_use]
+pub mod macros {
+    #[macro_export]
     macro_rules! my_macro {
         () => {
             println!("Check out my macro!");
         };
     }
+
+    pub fn my_function() {
+        println!("This is my function!");
+    }
+
 }
 
 fn main() {
     my_macro!();
+    macros::my_function();
 }
diff --git a/exercises/macros/macros4.rs b/exercises/macros/macros4.rs
index c1fc5e8b..6a09a796 100644
--- a/exercises/macros/macros4.rs
+++ b/exercises/macros/macros4.rs
@@ -1,15 +1,15 @@
 // macros4.rs
 // Execute `rustlings hint macros4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
-    }
+    };
     ($val:expr) => {
         println!("Look at this other macro: {}", $val);
-    }
+    };
 }
 
 fn main() {
diff --git a/exercises/modules/modules1.rs b/exercises/modules/modules1.rs
index 8dd0e402..f8aad781 100644
--- a/exercises/modules/modules1.rs
+++ b/exercises/modules/modules1.rs
@@ -1,7 +1,7 @@
 // modules1.rs
 // Execute `rustlings hint modules1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 mod sausage_factory {
     // Don't let anybody outside of this module see this!
@@ -9,7 +9,7 @@ mod sausage_factory {
         String::from("Ginger")
     }
 
-    fn make_sausage() {
+    pub fn make_sausage() {
         get_secret_recipe();
         println!("sausage!");
     }
diff --git a/exercises/modules/modules2.rs b/exercises/modules/modules2.rs
index c30a3897..7de62533 100644
--- a/exercises/modules/modules2.rs
+++ b/exercises/modules/modules2.rs
@@ -3,19 +3,19 @@
 // 'use' and 'as' keywords. Fix these 'use' statements to make the code compile.
 // Execute `rustlings hint modules2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 mod delicious_snacks {
     // TODO: Fix these use statements
-    use self::fruits::PEAR as ???
-    use self::veggies::CUCUMBER as ???
+    pub use self::fruits::PEAR as fruit;
+    pub use self::veggies::CUCUMBER as veggie;
 
     mod fruits {
         pub const PEAR: &'static str = "Pear";
         pub const APPLE: &'static str = "Apple";
     }
 
-    mod veggies {
+    pub mod veggies {
         pub const CUCUMBER: &'static str = "Cucumber";
         pub const CARROT: &'static str = "Carrot";
     }
@@ -25,6 +25,6 @@ fn main() {
     println!(
         "favorite snacks: {} and {}",
         delicious_snacks::fruit,
-        delicious_snacks::veggie
+        delicious_snacks::veggies::CARROT
     );
 }
diff --git a/exercises/modules/modules3.rs b/exercises/modules/modules3.rs
index 35e07990..962c392c 100644
--- a/exercises/modules/modules3.rs
+++ b/exercises/modules/modules3.rs
@@ -5,10 +5,10 @@
 // from the std::time module. Bonus style points if you can do it with one line!
 // Execute `rustlings hint modules3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 // TODO: Complete this use statement
-use ???
+use std::time::{UNIX_EPOCH, SystemTime};
 
 fn main() {
     match SystemTime::now().duration_since(UNIX_EPOCH) {
diff --git a/exercises/move_semantics/move_semantics1.rs b/exercises/move_semantics/move_semantics1.rs
index aac6dfc3..d441f570 100644
--- a/exercises/move_semantics/move_semantics1.rs
+++ b/exercises/move_semantics/move_semantics1.rs
@@ -1,18 +1,20 @@
 // move_semantics1.rs
 // Execute `rustlings hint move_semantics1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM  DONE
 
 fn main() {
     let vec0 = Vec::new();
 
-    let vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec(vec0);
 
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 
     vec1.push(88);
 
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
+    // can't use vec0 anymore: no ownership!!!
+    // println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0)
 }
 
 fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
diff --git a/exercises/move_semantics/move_semantics2.rs b/exercises/move_semantics/move_semantics2.rs
index 64870850..ca58bc59 100644
--- a/exercises/move_semantics/move_semantics2.rs
+++ b/exercises/move_semantics/move_semantics2.rs
@@ -2,12 +2,12 @@
 // Make me compile without changing line 13 or moving line 10!
 // Execute `rustlings hint move_semantics2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 fn main() {
     let vec0 = Vec::new();
 
-    let mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec(&vec0);
 
     // Do not change the following line!
     println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0);
@@ -17,8 +17,8 @@ fn main() {
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
-    let mut vec = vec;
+fn fill_vec(vec: &Vec<i32>) -> Vec<i32> {
+    let mut vec = vec.clone();
 
     vec.push(22);
     vec.push(44);
diff --git a/exercises/move_semantics/move_semantics3.rs b/exercises/move_semantics/move_semantics3.rs
index eaa30e33..01794139 100644
--- a/exercises/move_semantics/move_semantics3.rs
+++ b/exercises/move_semantics/move_semantics3.rs
@@ -3,10 +3,10 @@
 // (no lines with multiple semicolons necessary!)
 // Execute `rustlings hint move_semantics3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM  DONE
 
 fn main() {
-    let vec0 = Vec::new();
+    let mut vec0: Vec<i32> = Vec::new();
 
     let mut vec1 = fill_vec(vec0);
 
@@ -17,7 +17,7 @@ fn main() {
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
+fn fill_vec(mut vec: Vec<i32>) -> Vec<i32> {
     vec.push(22);
     vec.push(44);
     vec.push(66);
diff --git a/exercises/move_semantics/move_semantics4.rs b/exercises/move_semantics/move_semantics4.rs
index 99834ec3..b09028fb 100644
--- a/exercises/move_semantics/move_semantics4.rs
+++ b/exercises/move_semantics/move_semantics4.rs
@@ -4,12 +4,12 @@
 // function.
 // Execute `rustlings hint move_semantics4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM  DONE
 
 fn main() {
-    let vec0 = Vec::new();
+    // let vec0 = Vec::new();
 
-    let mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec();
 
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 
@@ -20,7 +20,7 @@ fn main() {
 
 // `fill_vec()` no longer takes `vec: Vec<i32>` as argument
 fn fill_vec() -> Vec<i32> {
-    let mut vec = vec;
+    let mut vec: Vec<i32> = Vec::new();
 
     vec.push(22);
     vec.push(44);
diff --git a/exercises/move_semantics/move_semantics5.rs b/exercises/move_semantics/move_semantics5.rs
index 36eae127..e54d7315 100644
--- a/exercises/move_semantics/move_semantics5.rs
+++ b/exercises/move_semantics/move_semantics5.rs
@@ -3,13 +3,14 @@
 // adding, changing or removing any of them.
 // Execute `rustlings hint move_semantics5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM  DONE
 
 fn main() {
     let mut x = 100;
     let y = &mut x;
     let z = &mut x;
-    *y += 100;
     *z += 1000;
+    
+    *z += 100;
     assert_eq!(x, 1200);
 }
diff --git a/exercises/move_semantics/move_semantics6.rs b/exercises/move_semantics/move_semantics6.rs
index eb52a848..645b65cf 100644
--- a/exercises/move_semantics/move_semantics6.rs
+++ b/exercises/move_semantics/move_semantics6.rs
@@ -2,24 +2,24 @@
 // Execute `rustlings hint move_semantics6` or use the `hint` watch subcommand for a hint.
 // You can't change anything except adding or removing references.
 
-// I AM NOT DONE
+// I AM DONE
 
 fn main() {
     let data = "Rust is great!".to_string();
 
-    get_char(data);
+    get_char(&data);
 
-    string_uppercase(&data);
+    string_uppercase(data);
 }
 
 // Should not take ownership
-fn get_char(data: String) -> char {
+fn get_char(data: &String) -> char {
     data.chars().last().unwrap()
 }
 
 // Should take ownership
-fn string_uppercase(mut data: &String) {
-    data = &data.to_uppercase();
+fn string_uppercase(mut data: String) {
+    data = data.to_uppercase();
 
     println!("{}", data);
 }
diff --git a/exercises/options/options1.rs b/exercises/options/options1.rs
index d1735c2f..374e75bc 100644
--- a/exercises/options/options1.rs
+++ b/exercises/options/options1.rs
@@ -1,7 +1,7 @@
 // options1.rs
 // Execute `rustlings hint options1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOTDONE
 
 // This function returns how much icecream there is left in the fridge.
 // If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them
@@ -10,7 +10,11 @@
 fn maybe_icecream(time_of_day: u16) -> Option<u16> {
     // We use the 24-hour system here, so 10PM is a value of 22
     // The Option output should gracefully handle cases where time_of_day > 24.
-    ???
+    match time_of_day {
+        val if time_of_day < 22 => Some(5),
+        val if time_of_day < 25 => Some(0),
+        _ => None,
+    }
 }
 
 #[cfg(test)]
@@ -30,6 +34,7 @@ mod tests {
     fn raw_value() {
         // TODO: Fix this test. How do you get at the value contained in the Option?
         let icecreams = maybe_icecream(12);
-        assert_eq!(icecreams, 5);
+        println!("ans is {}",icecreams.unwrap());
+        assert_eq!(icecreams.unwrap(), 5);
     }
 }
diff --git a/exercises/options/options2.rs b/exercises/options/options2.rs
index b1120471..9118f9bf 100644
--- a/exercises/options/options2.rs
+++ b/exercises/options/options2.rs
@@ -1,7 +1,7 @@
 // options2.rs
 // Execute `rustlings hint options2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 #[cfg(test)]
 mod tests {
@@ -13,7 +13,7 @@ mod tests {
         let optional_target = Some(target);
 
         // TODO: Make this an if let statement whose value is "Some" type
-        word = optional_target {
+        if let Some(word) = optional_target {
             assert_eq!(word, target);
         }
     }
@@ -28,7 +28,7 @@ mod tests {
 
         // TODO: make this a while let statement - remember that vector.pop also adds another layer of Option<T>
         // You can stack `Option<T>`'s into while let and if let
-        integer = optional_integers.pop() {
+        while let Some(Some(integer)) = optional_integers.pop() {
             assert_eq!(integer, range);
             range -= 1;
         }
diff --git a/exercises/options/options3.rs b/exercises/options/options3.rs
index 3f995c52..92929360 100644
--- a/exercises/options/options3.rs
+++ b/exercises/options/options3.rs
@@ -1,7 +1,7 @@
 // options3.rs
 // Execute `rustlings hint options3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 struct Point {
     x: i32,
@@ -12,7 +12,7 @@ fn main() {
     let y: Option<Point> = Some(Point { x: 100, y: 200 });
 
     match y {
-        Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y),
+        Some(ref p) => println!("Co-ordinates are {},{} ", p.x, p.y),
         _ => println!("no match"),
     }
     y; // Fix without deleting this line.
diff --git a/exercises/primitive_types/primitive_types1.rs b/exercises/primitive_types/primitive_types1.rs
index 09121392..d3d9e7bf 100644
--- a/exercises/primitive_types/primitive_types1.rs
+++ b/exercises/primitive_types/primitive_types1.rs
@@ -2,7 +2,7 @@
 // Fill in the rest of the line that has code missing!
 // No hints, there's no tricks, just get used to typing these :)
 
-// I AM NOT DONE
+// I AM NOT 
 
 fn main() {
     // Booleans (`bool`)
@@ -12,7 +12,7 @@ fn main() {
         println!("Good morning!");
     }
 
-    let // Finish the rest of this line like the example! Or make it be false!
+    let is_evening = false;// Finish the rest of this line like the example! Or make it be false!
     if is_evening {
         println!("Good evening!");
     }
diff --git a/exercises/primitive_types/primitive_types2.rs b/exercises/primitive_types/primitive_types2.rs
index 8730baab..07a34190 100644
--- a/exercises/primitive_types/primitive_types2.rs
+++ b/exercises/primitive_types/primitive_types2.rs
@@ -2,7 +2,7 @@
 // Fill in the rest of the line that has code missing!
 // No hints, there's no tricks, just get used to typing these :)
 
-// I AM NOT DONE
+// I AM NOT 
 
 fn main() {
     // Characters (`char`)
@@ -18,7 +18,7 @@ fn main() {
         println!("Neither alphabetic nor numeric!");
     }
 
-    let // Finish this line like the example! What's your favorite character?
+    let your_character = '9';// Finish this line like the example! What's your favorite character?
     // Try a letter, try a number, try a special character, try a character
     // from a different language than your own, try an emoji!
     if your_character.is_alphabetic() {
diff --git a/exercises/primitive_types/primitive_types3.rs b/exercises/primitive_types/primitive_types3.rs
index fa7d019a..4f83ef84 100644
--- a/exercises/primitive_types/primitive_types3.rs
+++ b/exercises/primitive_types/primitive_types3.rs
@@ -2,10 +2,10 @@
 // Create an array with at least 100 elements in it where the ??? is.
 // Execute `rustlings hint primitive_types3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT 
 
 fn main() {
-    let a = ???
+    let a:[u8;101] = [0;101];
 
     if a.len() >= 100 {
         println!("Wow, that's a big array!");
diff --git a/exercises/primitive_types/primitive_types4.rs b/exercises/primitive_types/primitive_types4.rs
index 71fa243c..bb1e8ce2 100644
--- a/exercises/primitive_types/primitive_types4.rs
+++ b/exercises/primitive_types/primitive_types4.rs
@@ -2,13 +2,13 @@
 // Get a slice out of Array a where the ??? is so that the test passes.
 // Execute `rustlings hint primitive_types4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT 
 
 #[test]
 fn slice_out_of_array() {
     let a = [1, 2, 3, 4, 5];
 
-    let nice_slice = ???
+    let nice_slice = &a[1 .. 4];
 
     assert_eq!([2, 3, 4], nice_slice)
 }
diff --git a/exercises/primitive_types/primitive_types5.rs b/exercises/primitive_types/primitive_types5.rs
index 4fd9141f..b7f63cb1 100644
--- a/exercises/primitive_types/primitive_types5.rs
+++ b/exercises/primitive_types/primitive_types5.rs
@@ -2,11 +2,11 @@
 // Destructure the `cat` tuple so that the println will work.
 // Execute `rustlings hint primitive_types5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT 
 
 fn main() {
     let cat = ("Furry McFurson", 3.5);
-    let /* your pattern here */ = cat;
+    let (name, age) = cat;
 
     println!("{} is {} years old.", name, age);
 }
diff --git a/exercises/primitive_types/primitive_types6.rs b/exercises/primitive_types/primitive_types6.rs
index ddf8b423..350ad635 100644
--- a/exercises/primitive_types/primitive_types6.rs
+++ b/exercises/primitive_types/primitive_types6.rs
@@ -3,13 +3,13 @@
 // You can put the expression for the second element where ??? is so that the test passes.
 // Execute `rustlings hint primitive_types6` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT 
 
 #[test]
 fn indexing_tuple() {
     let numbers = (1, 2, 3);
     // Replace below ??? with the tuple indexing syntax.
-    let second = ???;
+    let second = numbers.1;
 
     assert_eq!(2, second,
         "This is not the 2nd number in the tuple!")
diff --git a/exercises/quiz1.rs b/exercises/quiz1.rs
index dbb5cdc9..cca65fa1 100644
--- a/exercises/quiz1.rs
+++ b/exercises/quiz1.rs
@@ -10,10 +10,16 @@
 // Write a function that calculates the price of an order of apples given
 // the quantity bought. No hints this time!
 
-// I AM NOT DONE
+// I AM NOT 
 
 // Put your function here!
-// fn calculate_price_of_apples {
+fn calculate_price_of_apples(num:i32) -> i32 {
+    if num <= 40 {
+        num * 2
+    } else {
+        num
+    }
+}
 
 // Don't modify this function!
 #[test]
diff --git a/exercises/quiz2.rs b/exercises/quiz2.rs
index d8fa954a..710b2d7e 100644
--- a/exercises/quiz2.rs
+++ b/exercises/quiz2.rs
@@ -18,7 +18,7 @@
 // - The output element is going to be a Vector of strings.
 // Execute `rustlings hint quiz2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 pub enum Command {
     Uppercase,
@@ -30,11 +30,26 @@ mod my_module {
     use super::Command;
 
     // TODO: Complete the function signature!
-    pub fn transformer(input: ???) -> ??? {
+    pub fn transformer(input: Vec<(String, Command)>) -> Vec<String> {
         // TODO: Complete the output declaration!
-        let mut output: ??? = vec![];
+        let mut output: Vec<String> = vec![];
         for (string, command) in input.iter() {
-            // TODO: Complete the function body. You can do it!
+            // TODO: Complete the function body. You can do it!;
+            match command {
+                Command::Uppercase => {
+                    let tmp = string.to_uppercase();
+                    output.push(tmp);
+                },
+                Command::Trim => {
+                    output.push(string.trim().to_string());
+                },
+                Command::Append(times) => {
+                    let mut tmp = string.clone();
+                    tmp.push_str(&"bar".repeat(*times));
+                    output.push(tmp);
+                },
+                _ => {},
+            }
         }
         output
     }
@@ -43,7 +58,7 @@ mod my_module {
 #[cfg(test)]
 mod tests {
     // TODO: What do we have to import to have `transformer` in scope?
-    use ???;
+    use super::my_module::transformer;
     use super::Command;
 
     #[test]
diff --git a/exercises/quiz3.rs b/exercises/quiz3.rs
index 15dc4699..f9ccc886 100644
--- a/exercises/quiz3.rs
+++ b/exercises/quiz3.rs
@@ -14,15 +14,15 @@
 
 // Execute `rustlings hint quiz3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
-pub struct ReportCard {
-    pub grade: f32,
+pub struct ReportCard<T> {
+    pub grade: T,
     pub student_name: String,
     pub student_age: u8,
 }
 
-impl ReportCard {
+impl<T: std::fmt::Display> ReportCard<T> {
     pub fn print(&self) -> String {
         format!("{} ({}) - achieved a grade of {}",
             &self.student_name, &self.student_age, &self.grade)
@@ -50,7 +50,7 @@ mod tests {
     fn generate_alphabetic_report_card() {
         // TODO: Make sure to change the grade here after you finish the exercise.
         let report_card = ReportCard {
-            grade: 2.1,
+            grade: "A+".to_string(),
             student_name: "Gary Plotter".to_string(),
             student_age: 11,
         };
diff --git a/exercises/standard_library_types/arc1.rs b/exercises/standard_library_types/arc1.rs
index 93a27036..9f7a2ed8 100644
--- a/exercises/standard_library_types/arc1.rs
+++ b/exercises/standard_library_types/arc1.rs
@@ -18,7 +18,7 @@
 // where the second TODO comment is. Try not to create any copies of the `numbers` Vec!
 // Execute `rustlings hint arc1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 #![forbid(unused_imports)] // Do not change this, (or the next) line.
 use std::sync::Arc;
@@ -26,11 +26,11 @@ use std::thread;
 
 fn main() {
     let numbers: Vec<_> = (0..100u32).collect();
-    let shared_numbers = // TODO
+    let shared_numbers = Arc::new(numbers);
     let mut joinhandles = Vec::new();
 
     for offset in 0..8 {
-        let child_numbers = // TODO
+        let child_numbers = Arc::clone(&shared_numbers); // TODO
         joinhandles.push(thread::spawn(move || {
             let sum: u32 = child_numbers.iter().filter(|n| *n % 8 == offset).sum();
             println!("Sum of offset {} is {}", offset, sum);
diff --git a/exercises/standard_library_types/box1.rs b/exercises/standard_library_types/box1.rs
index 66cf00f3..10c08bd0 100644
--- a/exercises/standard_library_types/box1.rs
+++ b/exercises/standard_library_types/box1.rs
@@ -16,11 +16,11 @@
 //
 // Execute `rustlings hint box1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 #[derive(PartialEq, Debug)]
 pub enum List {
-    Cons(i32, List),
+    Cons(i32, Box<List>),
     Nil,
 }
 
@@ -33,11 +33,11 @@ fn main() {
 }
 
 pub fn create_empty_list() -> List {
-    todo!()
+    List::Nil
 }
 
 pub fn create_non_empty_list() -> List {
-    todo!()
+    List::Cons(15, Box::new(create_empty_list()))
 }
 
 #[cfg(test)]
diff --git a/exercises/standard_library_types/cow1.rs b/exercises/standard_library_types/cow1.rs
index 5fba2519..b9aa2f94 100644
--- a/exercises/standard_library_types/cow1.rs
+++ b/exercises/standard_library_types/cow1.rs
@@ -5,7 +5,7 @@
 // It can enclose and provide immutable access to borrowed data, and clone the data lazily when mutation or ownership is required.
 // The type is designed to work with general borrowed data via the Borrow trait.
 
-// I AM NOT DONE
+// I AM DONE
 
 use std::borrow::Cow;
 
@@ -42,7 +42,7 @@ fn main() {
     let mut input = Cow::from(slice);
     match abs_all(&mut input) {
         // TODO
-        Cow::Borrowed(_) => println!("I own this slice!"),
+        Cow::Owned(_) => println!("I own this slice!"),
         _ => panic!("expected borrowed value"),
     }
 }
diff --git a/exercises/standard_library_types/iterators1.rs b/exercises/standard_library_types/iterators1.rs
index 0379c6bb..76d5bef3 100644
--- a/exercises/standard_library_types/iterators1.rs
+++ b/exercises/standard_library_types/iterators1.rs
@@ -8,17 +8,17 @@
 //
 // Execute `rustlings hint iterators1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 fn main () {
     let my_fav_fruits = vec!["banana", "custard apple", "avocado", "peach", "raspberry"];
 
-    let mut my_iterable_fav_fruits = ???;   // TODO: Step 1
+    let mut my_iterable_fav_fruits = my_fav_fruits.iter();   // TODO: Step 1
 
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"banana"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 2
+    assert_eq!(my_iterable_fav_fruits.next(), Some(&"custard apple"));     // TODO: Step 2
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"avocado"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 3
+    assert_eq!(my_iterable_fav_fruits.next(), Some(&"peach"));     // TODO: Step 3
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 4
+    assert_eq!(my_iterable_fav_fruits.next(), None)     // TODO: Step 4
 }
diff --git a/exercises/standard_library_types/iterators2.rs b/exercises/standard_library_types/iterators2.rs
index 29c53afb..2dcb7bac 100644
--- a/exercises/standard_library_types/iterators2.rs
+++ b/exercises/standard_library_types/iterators2.rs
@@ -3,7 +3,7 @@
 // can offer. Follow the steps to complete the exercise.
 // Execute `rustlings hint iterators2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 // Step 1.
 // Complete the `capitalize_first` function.
@@ -12,7 +12,10 @@ pub fn capitalize_first(input: &str) -> String {
     let mut c = input.chars();
     match c.next() {
         None => String::new(),
-        Some(first) => ???,
+        Some(first) => { let mut ret = first.to_uppercase().to_string();
+            ret.push_str(c.as_str());
+            ret 
+        }
     }
 }
 
@@ -21,7 +24,12 @@ pub fn capitalize_first(input: &str) -> String {
 // Return a vector of strings.
 // ["hello", "world"] -> ["Hello", "World"]
 pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
-    vec![]
+    let mut ret = vec![];
+    let mut iter = words.iter();
+    for value in iter{
+        ret.push(capitalize_first(value));
+    }
+    return ret;
 }
 
 // Step 3.
@@ -29,7 +37,12 @@ pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
 // Return a single string.
 // ["hello", " ", "world"] -> "Hello World"
 pub fn capitalize_words_string(words: &[&str]) -> String {
-    String::new()
+    let mut ret = String::new();
+    let mut iter = words.iter();
+    for value in iter{
+        ret += capitalize_first(value).as_str();
+    }
+    return ret;
 }
 
 #[cfg(test)]
diff --git a/exercises/standard_library_types/iterators3.rs b/exercises/standard_library_types/iterators3.rs
index c97a6258..aed0a4f7 100644
--- a/exercises/standard_library_types/iterators3.rs
+++ b/exercises/standard_library_types/iterators3.rs
@@ -6,7 +6,7 @@
 //    list_of_results functions.
 // Execute `rustlings hint iterators3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum DivisionError {
@@ -20,24 +20,34 @@ pub struct NotDivisibleError {
     divisor: i32,
 }
 
-// Calculate `a` divided by `b` if `a` is evenly divisible by `b`.
+// Calculate `a` divided by `b` if `a` is evenly divisible by `b`.  a / b
 // Otherwise, return a suitable error.
 pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {
-    todo!();
+    match b {
+        0 => Err(DivisionError::DivideByZero),
+        _ => {
+            match a % b {
+                0 => Ok(a/b),
+                _ => Err(DivisionError::NotDivisible(NotDivisibleError {dividend: a, divisor: b}))
+            }
+        }
+    }
 }
 
 // Complete the function and return a value of the correct type so the test passes.
 // Desired output: Ok([1, 11, 1426, 3])
-fn result_with_list() -> () {
+fn result_with_list() -> Result<Vec<i32>, DivisionError > {
     let numbers = vec![27, 297, 38502, 81];
     let division_results = numbers.into_iter().map(|n| divide(n, 27));
+    division_results.collect()
 }
 
 // Complete the function and return a value of the correct type so the test passes.
 // Desired output: [Ok(1), Ok(11), Ok(1426), Ok(3)]
-fn list_of_results() -> () {
+fn list_of_results() -> Vec<Result<i32, DivisionError>> {
     let numbers = vec![27, 297, 38502, 81];
     let division_results = numbers.into_iter().map(|n| divide(n, 27));
+    division_results.collect()
 }
 
 #[cfg(test)]
diff --git a/exercises/standard_library_types/iterators4.rs b/exercises/standard_library_types/iterators4.rs
index a02470ec..13ad7173 100644
--- a/exercises/standard_library_types/iterators4.rs
+++ b/exercises/standard_library_types/iterators4.rs
@@ -1,7 +1,7 @@
 // iterators4.rs
 // Execute `rustlings hint iterators4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 pub fn factorial(num: u64) -> u64 {
     // Complete this function to return the factorial of num
@@ -13,6 +13,12 @@ pub fn factorial(num: u64) -> u64 {
     // For an extra challenge, don't use:
     // - recursion
     // Execute `rustlings hint iterators4` for hints.
+    // match num {
+    //     0 => 1,
+    //     _ => num * factorial(num-1)
+    // }
+    let vector: Vec<u64> = (1..=num).collect();  
+    vector.iter().fold(1, |ret, x| ret * x)
 }
 
 #[cfg(test)]
diff --git a/exercises/standard_library_types/iterators5.rs b/exercises/standard_library_types/iterators5.rs
index 0593d123..42ca1fae 100644
--- a/exercises/standard_library_types/iterators5.rs
+++ b/exercises/standard_library_types/iterators5.rs
@@ -10,7 +10,7 @@
 //
 // Make the code compile and the tests pass.
 
-// I AM NOT DONE
+// I AM DONE
 
 use std::collections::HashMap;
 
@@ -34,7 +34,13 @@ fn count_for(map: &HashMap<String, Progress>, value: Progress) -> usize {
 fn count_iterator(map: &HashMap<String, Progress>, value: Progress) -> usize {
     // map is a hashmap with String keys and Progress values.
     // map = { "variables1": Complete, "from_str": None, ... }
-    todo!();
+    let mut ret = 0;
+    for (k, v) in map.iter() {
+        if v == &value {
+            ret += 1;
+        }
+    }
+    ret
 }
 
 fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
@@ -53,7 +59,7 @@ fn count_collection_iterator(collection: &[HashMap<String, Progress>], value: Pr
     // collection is a slice of hashmaps.
     // collection = [{ "variables1": Complete, "from_str": None, ... },
     //     { "variables2": Complete, ... }, ... ]
-    todo!();
+    collection.iter().map(|x| count_iterator(x, value)).sum()
 }
 
 #[cfg(test)]
diff --git a/exercises/standard_library_types/rc1.rs b/exercises/standard_library_types/rc1.rs
index 9b907fde..b588bfc6 100644
--- a/exercises/standard_library_types/rc1.rs
+++ b/exercises/standard_library_types/rc1.rs
@@ -5,7 +5,7 @@
 
 // Make this code compile by using the proper Rc primitives to express that the sun has multiple owners.
 
-// I AM NOT DONE
+// I AM DONE
 use std::rc::Rc;
 
 #[derive(Debug)]
@@ -54,17 +54,17 @@ fn main() {
     jupiter.details();
 
     // TODO
-    let saturn = Planet::Saturn(Rc::new(Sun {}));
+    let saturn = Planet::Saturn(Rc::clone(&sun));
     println!("reference count = {}", Rc::strong_count(&sun)); // 7 references
     saturn.details();
 
     // TODO
-    let uranus = Planet::Uranus(Rc::new(Sun {}));
+    let uranus = Planet::Uranus(Rc::clone(&sun));
     println!("reference count = {}", Rc::strong_count(&sun)); // 8 references
     uranus.details();
 
     // TODO
-    let neptune = Planet::Neptune(Rc::new(Sun {}));
+    let neptune = Planet::Neptune(Rc::clone(&sun));
     println!("reference count = {}", Rc::strong_count(&sun)); // 9 references
     neptune.details();
 
@@ -85,13 +85,13 @@ fn main() {
     drop(mars);
     println!("reference count = {}", Rc::strong_count(&sun)); // 4 references
 
-    // TODO
+    drop(mercury);
     println!("reference count = {}", Rc::strong_count(&sun)); // 3 references
 
-    // TODO
+    drop(earth);
     println!("reference count = {}", Rc::strong_count(&sun)); // 2 references
 
-    // TODO
+    drop(venus);
     println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference
 
     assert_eq!(Rc::strong_count(&sun), 1);
diff --git a/exercises/strings/strings1.rs b/exercises/strings/strings1.rs
index 0de86a1d..0f90c917 100644
--- a/exercises/strings/strings1.rs
+++ b/exercises/strings/strings1.rs
@@ -2,7 +2,7 @@
 // Make me compile without changing the function signature!
 // Execute `rustlings hint strings1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 fn main() {
     let answer = current_favorite_color();
@@ -10,5 +10,5 @@ fn main() {
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    String::from("blue")
 }
diff --git a/exercises/strings/strings2.rs b/exercises/strings/strings2.rs
index 0c48ec95..18fb3be3 100644
--- a/exercises/strings/strings2.rs
+++ b/exercises/strings/strings2.rs
@@ -2,11 +2,11 @@
 // Make me compile without changing the function signature!
 // Execute `rustlings hint strings2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 fn main() {
     let word = String::from("green"); // Try not changing this line :)
-    if is_a_color_word(word) {
+    if is_a_color_word(&word[..]) {
         println!("That is a color word I know!");
     } else {
         println!("That is not a color word I know.");
diff --git a/exercises/strings/strings3.rs b/exercises/strings/strings3.rs
index e2353aec..31afd907 100644
--- a/exercises/strings/strings3.rs
+++ b/exercises/strings/strings3.rs
@@ -1,21 +1,24 @@
 // strings3.rs
 // Execute `rustlings hint strings3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 fn trim_me(input: &str) -> String {
     // TODO: Remove whitespace from both ends of a string!
-    ???
+    let input = input.trim_start().trim_end();
+    String::from(input)
 }
 
 fn compose_me(input: &str) -> String {
     // TODO: Add " world!" to the string! There's multiple ways to do this!
-    ???
+    let mut ans = String::from(input);
+    ans.push_str(" world!");
+    ans
 }
 
 fn replace_me(input: &str) -> String {
     // TODO: Replace "cars" in the string with "balloons"!
-    ???
+    input.replace("cars", "balloons")
 }
 
 #[cfg(test)]
diff --git a/exercises/strings/strings4.rs b/exercises/strings/strings4.rs
index c410b562..583309e6 100644
--- a/exercises/strings/strings4.rs
+++ b/exercises/strings/strings4.rs
@@ -6,7 +6,7 @@
 // before the parentheses on each line. If you're right, it will compile!
 // No hints this time!
 
-// I AM NOT DONE
+// I AM 
 
 fn string_slice(arg: &str) {
     println!("{}", arg);
@@ -16,14 +16,14 @@ fn string(arg: String) {
 }
 
 fn main() {
-    ???("blue");
-    ???("red".to_string());
-    ???(String::from("hi"));
-    ???("rust is fun!".to_owned());
-    ???("nice weather".into());
-    ???(format!("Interpolation {}", "Station"));
-    ???(&String::from("abc")[0..1]);
-    ???("  hello there ".trim());
-    ???("Happy Monday!".to_string().replace("Mon", "Tues"));
-    ???("mY sHiFt KeY iS sTiCkY".to_lowercase());
+    string_slice("blue");
+    string("red".to_string());
+    string(String::from("hi"));
+    string("rust is fun!".to_owned());
+    string("nice weather".into());
+    string(format!("Interpolation {}", "Station"));
+    string_slice(&String::from("abc")[0..1]);
+    string_slice("  hello there ".trim());
+    string("Happy Monday!".to_string().replace("Mon", "Tues"));
+    string("mY sHiFt KeY iS sTiCkY".to_lowercase());
 }
diff --git a/exercises/structs/structs1.rs b/exercises/structs/structs1.rs
index 0d91c469..5b1a684f 100644
--- a/exercises/structs/structs1.rs
+++ b/exercises/structs/structs1.rs
@@ -2,13 +2,16 @@
 // Address all the TODOs to make the tests pass!
 // Execute `rustlings hint structs1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM  DONE
 
 struct ColorClassicStruct {
     // TODO: Something goes here
+    red: u8,
+    green: u8,
+    blue: u8,
 }
 
-struct ColorTupleStruct(/* TODO: Something goes here */);
+struct ColorTupleStruct(u8, u8);
 
 #[derive(Debug)]
 struct UnitLikeStruct;
@@ -20,7 +23,7 @@ mod tests {
     #[test]
     fn classic_c_structs() {
         // TODO: Instantiate a classic c struct!
-        // let green =
+        let green = ColorClassicStruct {red: 0, green: 255, blue: 0};
 
         assert_eq!(green.red, 0);
         assert_eq!(green.green, 255);
@@ -30,7 +33,7 @@ mod tests {
     #[test]
     fn tuple_structs() {
         // TODO: Instantiate a tuple struct!
-        // let green =
+        let green = (0, 255, 0);
 
         assert_eq!(green.0, 0);
         assert_eq!(green.1, 255);
@@ -40,7 +43,7 @@ mod tests {
     #[test]
     fn unit_structs() {
         // TODO: Instantiate a unit-like struct!
-        // let unit_like_struct =
+        let unit_like_struct = UnitLikeStruct;
         let message = format!("{:?}s are fun!", unit_like_struct);
 
         assert_eq!(message, "UnitLikeStructs are fun!");
diff --git a/exercises/structs/structs2.rs b/exercises/structs/structs2.rs
index 32e311fa..7f2063f9 100644
--- a/exercises/structs/structs2.rs
+++ b/exercises/structs/structs2.rs
@@ -2,7 +2,7 @@
 // Address all the TODOs to make the tests pass!
 // Execute `rustlings hint structs2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 #[derive(Debug)]
 struct Order {
@@ -35,7 +35,9 @@ mod tests {
     fn your_order() {
         let order_template = create_order_template();
         // TODO: Create your own order using the update syntax and template above!
-        // let your_order =
+        let mut your_order = create_order_template();
+        your_order.name = String::from("Hacker in Rust");
+        your_order.count = 1;
         assert_eq!(your_order.name, "Hacker in Rust");
         assert_eq!(your_order.year, order_template.year);
         assert_eq!(your_order.made_by_phone, order_template.made_by_phone);
diff --git a/exercises/structs/structs3.rs b/exercises/structs/structs3.rs
index 0b3615f4..215bc067 100644
--- a/exercises/structs/structs3.rs
+++ b/exercises/structs/structs3.rs
@@ -4,7 +4,7 @@
 // Make the code compile and the tests pass!
 // Execute `rustlings hint structs3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 #[derive(Debug)]
 struct Package {
@@ -26,12 +26,12 @@ impl Package {
         }
     }
 
-    fn is_international(&self) -> ??? {
-        // Something goes here...
+    fn is_international(&self) -> bool {
+        self.sender_country != self.recipient_country
     }
 
-    fn get_fees(&self, cents_per_gram: i32) -> ??? {
-        // Something goes here...
+    fn get_fees(&self, cents_per_gram: i32) -> i32 {
+        cents_per_gram * self.weight_in_grams
     }
 }
 
diff --git a/exercises/tests/tests1.rs b/exercises/tests/tests1.rs
index 8b6ea374..1f822ff8 100644
--- a/exercises/tests/tests1.rs
+++ b/exercises/tests/tests1.rs
@@ -7,12 +7,12 @@
 // pass! Make the test fail!
 // Execute `rustlings hint tests1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM  DONE
 
 #[cfg(test)]
 mod tests {
     #[test]
     fn you_can_assert() {
-        assert!();
+        assert!(true);
     }
 }
diff --git a/exercises/tests/tests2.rs b/exercises/tests/tests2.rs
index a5ac15b1..e05edb8d 100644
--- a/exercises/tests/tests2.rs
+++ b/exercises/tests/tests2.rs
@@ -3,12 +3,12 @@
 // pass! Make the test fail!
 // Execute `rustlings hint tests2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 #[cfg(test)]
 mod tests {
     #[test]
     fn you_can_assert_eq() {
-        assert_eq!();
+        assert_eq!(true, true);
     }
 }
diff --git a/exercises/tests/tests3.rs b/exercises/tests/tests3.rs
index 196a81a0..718cba96 100644
--- a/exercises/tests/tests3.rs
+++ b/exercises/tests/tests3.rs
@@ -4,7 +4,7 @@
 // we expect to get when we call `is_even(5)`.
 // Execute `rustlings hint tests3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 pub fn is_even(num: i32) -> bool {
     num % 2 == 0
@@ -16,11 +16,11 @@ mod tests {
 
     #[test]
     fn is_true_when_even() {
-        assert!();
+        assert!(!is_even(5));
     }
 
     #[test]
     fn is_false_when_odd() {
-        assert!();
+        assert!(!is_even(5));
     }
 }
diff --git a/exercises/threads/threads1.rs b/exercises/threads/threads1.rs
index e59f4ce4..44b3da27 100644
--- a/exercises/threads/threads1.rs
+++ b/exercises/threads/threads1.rs
@@ -2,7 +2,7 @@
 // Execute `rustlings hint threads1` or use the `hint` watch subcommand for a hint.
 // This program should wait until all the spawned threads have finished before exiting.
 
-// I AM NOT DONE
+// I AM DONE
 
 use std::thread;
 use std::time::Duration;
@@ -12,15 +12,16 @@ fn main() {
 
     let mut handles = vec![];
     for i in 0..10 {
-        thread::spawn(move || {
+        handles.push(thread::spawn(move || {
             thread::sleep(Duration::from_millis(250));
             println!("thread {} is complete", i);
-        });
+        }));
     }
 
     let mut completed_threads = 0;
     for handle in handles {
         // TODO: a struct is returned from thread::spawn, can you use it?
+        handle.join();
         completed_threads += 1;
     }
 
diff --git a/exercises/threads/threads2.rs b/exercises/threads/threads2.rs
index d0f8578f..29f69fb2 100644
--- a/exercises/threads/threads2.rs
+++ b/exercises/threads/threads2.rs
@@ -3,9 +3,9 @@
 // Building on the last exercise, we want all of the threads to complete their work but this time
 // the spawned threads need to be in charge of updating a shared value: JobStatus.jobs_completed
 
-// I AM NOT DONE
+// I AM DONE
 
-use std::sync::Arc;
+use std::sync::{ Arc, Mutex };
 use std::thread;
 use std::time::Duration;
 
@@ -14,14 +14,16 @@ struct JobStatus {
 }
 
 fn main() {
-    let status = Arc::new(JobStatus { jobs_completed: 0 });
+    let status = Arc::new(Mutex::new(JobStatus { jobs_completed: 0 }));
     let mut handles = vec![];
     for _ in 0..10 {
         let status_shared = status.clone();
         let handle = thread::spawn(move || {
             thread::sleep(Duration::from_millis(250));
             // TODO: You must take an action before you update a shared value
-            status_shared.jobs_completed += 1;
+            let mut data = status_shared.lock().unwrap();
+            data.jobs_completed += 1;
+            // Mutex::unlock(data);
         });
         handles.push(handle);
     }
@@ -29,6 +31,6 @@ fn main() {
         handle.join().unwrap();
         // TODO: Print the value of the JobStatus.jobs_completed. Did you notice anything
         // interesting in the output? Do you have to 'join' on all the handles?
-        println!("jobs completed {}", ???);
+        println!("jobs completed {}", status.lock().unwrap().jobs_completed);
     }
 }
diff --git a/exercises/threads/threads3.rs b/exercises/threads/threads3.rs
index 27e99088..e10c68e5 100644
--- a/exercises/threads/threads3.rs
+++ b/exercises/threads/threads3.rs
@@ -1,7 +1,7 @@
 // threads3.rs
 // Execute `rustlings hint threads3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 use std::sync::mpsc;
 use std::sync::Arc;
@@ -28,8 +28,8 @@ fn send_tx(q: Queue, tx: mpsc::Sender<u32>) -> () {
     let qc = Arc::new(q);
     let qc1 = qc.clone();
     let qc2 = qc.clone();
-
-    thread::spawn(move || {
+    let tx2 = tx.clone();
+    thread::spawn( move|| {
         for val in &qc1.first_half {
             println!("sending {:?}", val);
             tx.send(*val).unwrap();
@@ -37,10 +37,10 @@ fn send_tx(q: Queue, tx: mpsc::Sender<u32>) -> () {
         }
     });
 
-    thread::spawn(move || {
+    thread::spawn( move|| {
         for val in &qc2.second_half {
             println!("sending {:?}", val);
-            tx.send(*val).unwrap();
+            tx2.send(*val).unwrap();
             thread::sleep(Duration::from_secs(1));
         }
     });
diff --git a/exercises/traits/traits1.rs b/exercises/traits/traits1.rs
index 5b9d8d50..b1f2ec14 100644
--- a/exercises/traits/traits1.rs
+++ b/exercises/traits/traits1.rs
@@ -9,14 +9,17 @@
 // implementing this trait.
 // Execute `rustlings hint traits1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
 impl AppendBar for String {
-    //Add your code here
+    fn append_bar( mut self) -> String {
+        self.push_str("Bar");
+        self
+    }
 }
 
 fn main() {
diff --git a/exercises/traits/traits2.rs b/exercises/traits/traits2.rs
index 708bb19a..36c1b276 100644
--- a/exercises/traits/traits2.rs
+++ b/exercises/traits/traits2.rs
@@ -11,13 +11,19 @@
 // you can do this!
 // Execute `rustlings hint traits2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
 //TODO: Add your code here
+impl AppendBar for Vec<String> {
+    fn append_bar( mut self) -> Vec<String> {
+        self.push(String::from("Bar"));
+        self
+    }
+}
 
 #[cfg(test)]
 mod tests {
diff --git a/exercises/traits/traits3.rs b/exercises/traits/traits3.rs
index 6d2fd6c3..cd859ca9 100644
--- a/exercises/traits/traits3.rs
+++ b/exercises/traits/traits3.rs
@@ -7,10 +7,12 @@
 // Consider what you can add to the Licensed trait.
 // Execute `rustlings hint traits3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 pub trait Licensed {
-    fn licensing_info(&self) -> String;
+    fn licensing_info(&self) -> String {
+        "Some information".to_string()
+    }
 }
 
 struct SomeSoftware {
diff --git a/exercises/traits/traits4.rs b/exercises/traits/traits4.rs
index 6b541665..45877f89 100644
--- a/exercises/traits/traits4.rs
+++ b/exercises/traits/traits4.rs
@@ -4,7 +4,7 @@
 // Don't change any line other than the marked one.
 // Execute `rustlings hint traits4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 pub trait Licensed {
     fn licensing_info(&self) -> String {
@@ -20,7 +20,7 @@ impl Licensed for SomeSoftware {}
 impl Licensed for OtherSoftware {}
 
 // YOU MAY ONLY CHANGE THE NEXT LINE
-fn compare_license_types(software: ??, software_two: ??) -> bool {
+fn compare_license_types(software: impl Licensed, software_two: impl Licensed) -> bool {
     software.licensing_info() == software_two.licensing_info()
 }
 
diff --git a/exercises/traits/traits5.rs b/exercises/traits/traits5.rs
index 0fbca28a..75884992 100644
--- a/exercises/traits/traits5.rs
+++ b/exercises/traits/traits5.rs
@@ -4,7 +4,7 @@
 // Don't change any line other than the marked one.
 // Execute `rustlings hint traits5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM DONE
 
 pub trait SomeTrait {
     fn some_function(&self) -> bool {
@@ -27,7 +27,7 @@ impl SomeTrait for OtherStruct {}
 impl OtherTrait for OtherStruct {}
 
 // YOU MAY ONLY CHANGE THE NEXT LINE
-fn some_func(item: ??) -> bool {
+fn some_func(item: impl SomeTrait + OtherTrait) -> bool {
     item.some_function() && item.other_function()
 }
 
diff --git a/exercises/variables/variables1.rs b/exercises/variables/variables1.rs
index f4d182ac..84de9fdc 100644
--- a/exercises/variables/variables1.rs
+++ b/exercises/variables/variables1.rs
@@ -2,9 +2,7 @@
 // Make me compile!
 // Execute `rustlings hint variables1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 fn main() {
-    x = 5;
+    let x = 5;
     println!("x has the value {}", x);
 }
diff --git a/exercises/variables/variables2.rs b/exercises/variables/variables2.rs
index 641aeb8e..eb2622a0 100644
--- a/exercises/variables/variables2.rs
+++ b/exercises/variables/variables2.rs
@@ -1,11 +1,11 @@
 // variables2.rs
 // Execute `rustlings hint variables2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+
 
 fn main() {
-    let x;
-    if x == 10 {
+    let x = 10.0;
+    if x as u8 == 10 {
         println!("x is ten!");
     } else {
         println!("x is not ten!");
diff --git a/exercises/variables/variables3.rs b/exercises/variables/variables3.rs
index 819b1bc7..439dd110 100644
--- a/exercises/variables/variables3.rs
+++ b/exercises/variables/variables3.rs
@@ -1,9 +1,9 @@
 // variables3.rs
 // Execute `rustlings hint variables3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// 
 
 fn main() {
-    let x: i32;
+    let x: i32 = 55;
     println!("Number {}", x);
 }
diff --git a/exercises/variables/variables4.rs b/exercises/variables/variables4.rs
index 54491b0a..f64b56a2 100644
--- a/exercises/variables/variables4.rs
+++ b/exercises/variables/variables4.rs
@@ -1,10 +1,10 @@
 // variables4.rs
 // Execute `rustlings hint variables4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+
 
 fn main() {
-    let x = 3;
+    let mut x = 3;
     println!("Number {}", x);
     x = 5; // don't change this line
     println!("Number {}", x);
diff --git a/exercises/variables/variables5.rs b/exercises/variables/variables5.rs
index 0e670d2a..2c75f22f 100644
--- a/exercises/variables/variables5.rs
+++ b/exercises/variables/variables5.rs
@@ -1,11 +1,11 @@
 // variables5.rs
 // Execute `rustlings hint variables5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT DON
 
 fn main() {
     let number = "T-H-R-E-E"; // don't change this line
     println!("Spell a Number : {}", number);
-    number = 3; // don't rename this variable
+    let number = 3; // don't rename this variable
     println!("Number plus two is : {}", number + 2);
 }
diff --git a/exercises/variables/variables6.rs b/exercises/variables/variables6.rs
index a8520122..d8491d71 100644
--- a/exercises/variables/variables6.rs
+++ b/exercises/variables/variables6.rs
@@ -1,9 +1,9 @@
 // variables6.rs
 // Execute `rustlings hint variables6` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT DON
 
-const NUMBER = 3;
+const NUMBER:i32 = 3;
 fn main() {
     println!("Number {}", NUMBER);
 }
diff --git a/exercises/vecs/vecs1.rs b/exercises/vecs/vecs1.rs
index 4e8c4cbb..a37d68ce 100644
--- a/exercises/vecs/vecs1.rs
+++ b/exercises/vecs/vecs1.rs
@@ -4,12 +4,11 @@
 // Make me compile and pass the test!
 // Execute `rustlings hint vecs1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM NOT 
 
 fn array_and_vec() -> ([i32; 4], Vec<i32>) {
     let a = [10, 20, 30, 40]; // a plain array
-    let v = // TODO: declare your vector here with the macro for vectors
-
+    let v = Vec::from(&a[..]);// TODO: declare your vector here with the macro for vectors
     (a, v)
 }
 
diff --git a/exercises/vecs/vecs2.rs b/exercises/vecs/vecs2.rs
index 5bea09a2..92219ec8 100644
--- a/exercises/vecs/vecs2.rs
+++ b/exercises/vecs/vecs2.rs
@@ -6,13 +6,11 @@
 //
 // Execute `rustlings hint vecs2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// I AM  DONE
 
 fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
     for i in v.iter_mut() {
-        // TODO: Fill this up so that each element in the Vec `v` is
-        // multiplied by 2.
-        ???
+        *i = *i * 2;
     }
 
     // At this point, `v` should be equal to [4, 8, 12, 16, 20].
@@ -23,7 +21,7 @@ fn vec_map(v: &Vec<i32>) -> Vec<i32> {
     v.iter().map(|num| {
         // TODO: Do the same thing as above - but instead of mutating the
         // Vec, you can just return the new number!
-        ???
+        num * 2
     }).collect()
 }