diff --git a/Cargo.lock b/Cargo.lock
index 3d04953d..2c29925c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -459,7 +459,7 @@ checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
 
 [[package]]
 name = "rustlings"
-version = "5.4.0"
+version = "5.4.1"
 dependencies = [
  "argh",
  "assert_cmd",
diff --git a/exercises/enums/enums1.rs b/exercises/enums/enums1.rs
index 511ba740..4e93f8d9 100644
--- a/exercises/enums/enums1.rs
+++ b/exercises/enums/enums1.rs
@@ -1,11 +1,14 @@
 // enums1.rs
 // No hints this time! ;)
 
-// I AM NOT 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 167a6b2e..0f772cc4 100644
--- a/exercises/enums/enums2.rs
+++ b/exercises/enums/enums2.rs
@@ -1,11 +1,14 @@
 // enums2.rs
 // Execute `rustlings hint enums2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[derive(Debug)]
 enum Message {
     // TODO: define the different variants used below
+    Move{x:usize, y:usize},
+    Echo(String),
+    ChangeColor(usize, usize, usize),
+    Quit,
 }
 
 impl Message {
diff --git a/exercises/enums/enums3.rs b/exercises/enums/enums3.rs
index a2a9d586..e9254486 100644
--- a/exercises/enums/enums3.rs
+++ b/exercises/enums/enums3.rs
@@ -2,10 +2,15 @@
 // 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
+
+use core::panic;
 
 enum Message {
     // TODO: implement the message variant types based on their usage below
+    ChangeColor(u8, u8, u8),
+    Echo(String),
+    Move(Point),
+    Quit,
 }
 
 struct Point {
@@ -39,9 +44,15 @@ impl State {
     fn process(&mut self, message: Message) {
         // TODO: create a match expression to process the different message variants
         // Remember: When passing a tuple as a function argument, you'll need extra parentheses: fn function((t, u, p, l, e))
+        match message {
+            Message::ChangeColor(r, g, b) => self.change_color((r,g,b)),
+            Message::Echo(string) => self.echo(string),
+            Message::Move(point) => self.move_position(point),
+            Message::Quit => self.quit(),
+            
+        }
     }
 }
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -63,4 +74,6 @@ mod tests {
         assert_eq!(state.position.y, 15);
         assert_eq!(state.quit, true);
     }
+
+    
 }
diff --git a/exercises/error_handling/errors1.rs b/exercises/error_handling/errors1.rs
index bcee9723..f2f96cb6 100644
--- a/exercises/error_handling/errors1.rs
+++ b/exercises/error_handling/errors1.rs
@@ -5,14 +5,13 @@
 // 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
 
-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(format!("`name` was empty; it must be nonempty."))
     } 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..3e51bb2b 100644
--- a/exercises/error_handling/errors2.rs
+++ b/exercises/error_handling/errors2.rs
@@ -17,16 +17,20 @@
 // one is a lot shorter!
 // Execute `rustlings hint errors2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT 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>();
+    Ok(item_quantity.parse::<i32>()? * cost_per_item + processing_fee)
+    // match item_quantity.parse::<i32>() {
+    //     Ok(qty) => Ok(qty * cost_per_item + processing_fee),
+    //     Err(err) => Err(err)
+    // }
 
-    Ok(qty * cost_per_item + processing_fee)
+    
 }
 
 #[cfg(test)]
diff --git a/exercises/error_handling/errors3.rs b/exercises/error_handling/errors3.rs
index a2d2d190..317c5b51 100644
--- a/exercises/error_handling/errors3.rs
+++ b/exercises/error_handling/errors3.rs
@@ -4,11 +4,10 @@
 // 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
 
-use std::num::ParseIntError;
+use std::{num::ParseIntError,error::Error};
 
-fn main() {
+fn main() -> Result<(), Box<dyn Error> > {
     let mut tokens = 100;
     let pretend_user_input = "8";
 
@@ -20,6 +19,7 @@ fn main() {
         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..5c742b7e 100644
--- a/exercises/error_handling/errors4.rs
+++ b/exercises/error_handling/errors4.rs
@@ -1,7 +1,6 @@
 // errors4.rs
 // Execute `rustlings hint errors4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[derive(PartialEq, Debug)]
 struct PositiveNonzeroInteger(u64);
@@ -15,7 +14,11 @@ 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))
+        
+        if value.is_negative() {Err(CreationError::Negative)}
+        else if value.is_positive() {Ok(PositiveNonzeroInteger(value as u64))} 
+        else {Err(CreationError::Zero)}
+        
     }
 }
 
diff --git a/exercises/error_handling/errors5.rs b/exercises/error_handling/errors5.rs
index eb5506cb..cce0ce26 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
 
 use std::error;
+use std::error::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>> {
     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 8097b490..07ec2963 100644
--- a/exercises/error_handling/errors6.rs
+++ b/exercises/error_handling/errors6.rs
@@ -8,7 +8,6 @@
 
 // Execute `rustlings hint errors6` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 use std::num::ParseIntError;
 
@@ -24,14 +23,25 @@ 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) -> Result<PositiveNonzeroInteger, ParsePosNonzeroError> {
     // TODO: change this to return an appropriate error instead of panicking
     // when `parse()` returns an error.
-    let x: i64 = s.parse().unwrap();
-    PositiveNonzeroInteger::new(x).map_err(ParsePosNonzeroError::from_creation)
+    match s.parse::<i64>().map_err(ParsePosNonzeroError::from_parseint)  {
+        Ok(x) => if x.is_positive() {
+            Ok(PositiveNonzeroInteger(x.try_into().unwrap()))
+        } else if x.is_negative() {
+            Err(ParsePosNonzeroError::from_creation(CreationError::Negative))
+        } else {
+            Err(ParsePosNonzeroError::from_creation(CreationError::Zero))
+        }
+        Err(err) => Err(err)
+    }  
+    
 }
 
 // Don't change anything below this line.
diff --git a/exercises/functions/functions1.rs b/exercises/functions/functions1.rs
index 03d8af70..24c47b0f 100644
--- a/exercises/functions/functions1.rs
+++ b/exercises/functions/functions1.rs
@@ -1,8 +1,9 @@
 // functions1.rs
 // Execute `rustlings hint functions1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     call_me();
 }
+
+fn call_me() {}
\ No newline at end of file
diff --git a/exercises/functions/functions2.rs b/exercises/functions/functions2.rs
index 7d40a578..759d2273 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
+
 
 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..402bb79b 100644
--- a/exercises/functions/functions3.rs
+++ b/exercises/functions/functions3.rs
@@ -1,10 +1,9 @@
 // functions3.rs
 // Execute `rustlings hint functions3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
-    call_me();
+    call_me(2);
 }
 
 fn call_me(num: u32) {
diff --git a/exercises/functions/functions4.rs b/exercises/functions/functions4.rs
index 65d5be4f..52ae252b 100644
--- a/exercises/functions/functions4.rs
+++ b/exercises/functions/functions4.rs
@@ -7,14 +7,13 @@
 // in the signatures for now. If anything, this is a good way to peek ahead
 // to future exercises!)
 
-// I AM NOT DONE
 
 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..3da51720 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
+
 
 fn main() {
     let answer = square(3);
@@ -9,5 +9,5 @@ fn main() {
 }
 
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }
diff --git a/exercises/generics/generics1.rs b/exercises/generics/generics1.rs
index 4c34ae47..74ca9217 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
+
 
 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..a6d35218 100644
--- a/exercises/generics/generics2.rs
+++ b/exercises/generics/generics2.rs
@@ -3,14 +3,13 @@
 
 // Execute `rustlings hint generics2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT 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..f8ce8a89 100644
--- a/exercises/hashmaps/hashmaps1.rs
+++ b/exercises/hashmaps/hashmaps1.rs
@@ -10,15 +10,16 @@
 //
 // Execute `rustlings hint hashmaps1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 use std::collections::HashMap;
 
 fn fruit_basket() -> HashMap<String, u32> {
-    let mut basket = // TODO: declare your hash map here.
+    let mut basket = HashMap::new();
 
     // Two bananas are already given for you :)
     basket.insert(String::from("banana"), 2);
+    basket.insert(String::from("blueberries"), 5);
+    basket.insert(String::from("apples"), 3);
 
     // TODO: Put more fruits in your basket here.
 
diff --git a/exercises/hashmaps/hashmaps2.rs b/exercises/hashmaps/hashmaps2.rs
index 454b3e1d..358d36e7 100644
--- a/exercises/hashmaps/hashmaps2.rs
+++ b/exercises/hashmaps/hashmaps2.rs
@@ -11,7 +11,6 @@
 //
 // Execute `rustlings hint hashmaps2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 use std::collections::HashMap;
 
@@ -34,9 +33,9 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
     ];
 
     for fruit in fruit_kinds {
-        // TODO: Put new fruits if not already present. Note that you
-        // are not allowed to put any type of fruit that's already
-        // present!
+        if let None=basket.get(&fruit) {
+            basket.insert(fruit, 1);
+        }
     }
 }
 
diff --git a/exercises/hashmaps/hashmaps3.rs b/exercises/hashmaps/hashmaps3.rs
index ad3baa68..8d39c97e 100644
--- a/exercises/hashmaps/hashmaps3.rs
+++ b/exercises/hashmaps/hashmaps3.rs
@@ -14,7 +14,6 @@
 
 // Execute `rustlings hint hashmaps3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 use std::collections::HashMap;
 
@@ -31,15 +30,28 @@ fn build_scores_table(results: String) -> HashMap<String, Team> {
 
     for r in results.lines() {
         let v: Vec<&str> = r.split(',').collect();
-        let team_1_name = v[0].to_string();
-        let team_1_score: u8 = v[2].parse().unwrap();
-        let team_2_name = v[1].to_string();
-        let team_2_score: u8 = v[3].parse().unwrap();
+        let mut team_1 = Team {
+            name:v[0].to_string(), 
+            goals_scored:v[2].parse().unwrap(),
+            goals_conceded:v[3].parse().unwrap()};
+        let mut team_2 = Team {
+            name:v[1].to_string(),
+            goals_scored: v[3].parse().unwrap(),
+            goals_conceded: v[2].parse().unwrap()};
+        
         // TODO: Populate the scores table with details extracted from the
         // current line. Keep in mind that goals scored by team_1
         // will be the number of goals conceded from team_2, and similarly
         // goals scored by team_2 will be the number of goals conceded by
         // team_1.
+        for mut team in [team_1, team_2] {
+            if let Some((_,team_existing_scores)) = scores.get_key_value(&team.name) {
+                team.goals_scored += team_existing_scores.goals_scored;
+                team.goals_conceded += team_existing_scores.goals_conceded;
+            }
+            scores.insert(team.name.to_string(), team);
+        }
+        
     }
     scores
 }
diff --git a/exercises/if/if1.rs b/exercises/if/if1.rs
index 587e03f8..03ee7957 100644
--- a/exercises/if/if1.rs
+++ b/exercises/if/if1.rs
@@ -1,13 +1,12 @@
 // if1.rs
 // Execute `rustlings hint if1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+
 
 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 if b>a {b}
+    else {panic!("numbers are the same!")}
 }
 
 // Don't mind this for now :)
diff --git a/exercises/if/if2.rs b/exercises/if/if2.rs
index effddbb6..01248e03 100644
--- a/exercises/if/if2.rs
+++ b/exercises/if/if2.rs
@@ -4,14 +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
+
 
 pub fn foo_if_fizz(fizzish: &str) -> &str {
-    if fizzish == "fizz" {
-        "foo"
-    } else {
-        1
+    match fizzish {
+        "fizz" => "foo",
+        "fuzz" => "bar",
+        _ => "baz",
     }
+    
 }
 
 // No test changes needed!
diff --git a/exercises/intro/intro1.rs b/exercises/intro/intro1.rs
index cfc55c30..54889778 100644
--- a/exercises/intro/intro1.rs
+++ b/exercises/intro/intro1.rs
@@ -9,8 +9,6 @@
 // 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");
     println!(r#"       welcome to...                      "#);
diff --git a/exercises/intro/intro2.rs b/exercises/intro/intro2.rs
index efc1af20..a21c8bb8 100644
--- a/exercises/intro/intro2.rs
+++ b/exercises/intro/intro2.rs
@@ -2,8 +2,8 @@
 // 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/iterators/iterators1.rs b/exercises/iterators/iterators1.rs
index f9cc3b39..588394d3 100644
--- a/exercises/iterators/iterators1.rs
+++ b/exercises/iterators/iterators1.rs
@@ -8,17 +8,16 @@
 //
 // Execute `rustlings hint iterators1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT 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/iterators/iterators2.rs b/exercises/iterators/iterators2.rs
index 29c53afb..489ff220 100644
--- a/exercises/iterators/iterators2.rs
+++ b/exercises/iterators/iterators2.rs
@@ -3,7 +3,6 @@
 // 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
 
 // Step 1.
 // Complete the `capitalize_first` function.
@@ -12,7 +11,7 @@ pub fn capitalize_first(input: &str) -> String {
     let mut c = input.chars();
     match c.next() {
         None => String::new(),
-        Some(first) => ???,
+        Some(first) => first.to_uppercase().to_string()+c.as_str()
     }
 }
 
@@ -21,7 +20,15 @@ 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 capitalized_words_vec:Vec<String>= Vec::new();
+    // for word in words {
+    //     capitalized_words_vec.push(capitalize_first(&word));
+    // }
+    // capitalized_words_vec
+    let iter = words.iter();
+    iter.for_each(|word| capitalized_words_vec.push(capitalize_first(word)));
+    capitalized_words_vec
+    
 }
 
 // Step 3.
@@ -29,7 +36,13 @@ 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 capitalized_words_string = String::new();
+    // for word in words {
+    //     capitalized_words_string += capitalize_first(word).as_str();
+    // }
+    let iter = words.iter();
+    iter.for_each(|word| capitalized_words_string += capitalize_first(word).as_str());
+    capitalized_words_string
 }
 
 #[cfg(test)]
diff --git a/exercises/iterators/iterators3.rs b/exercises/iterators/iterators3.rs
index c97a6258..ec1773d0 100644
--- a/exercises/iterators/iterators3.rs
+++ b/exercises/iterators/iterators3.rs
@@ -6,7 +6,9 @@
 //    list_of_results functions.
 // Execute `rustlings hint iterators3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+use std::result::Result;
+
+
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum DivisionError {
@@ -23,21 +25,51 @@ pub struct NotDivisibleError {
 // Calculate `a` divided by `b` if `a` is evenly divisible by `b`.
 // Otherwise, return a suitable error.
 pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {
-    todo!();
+    if b==0 {
+        Err(DivisionError::DivideByZero)
+    }
+    else if a%b==0 {
+        Ok(a/b)        
+    }
+    else {
+        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>,()> {
     let numbers = vec![27, 297, 38502, 81];
-    let division_results = numbers.into_iter().map(|n| divide(n, 27));
+    Ok(numbers.into_iter().map(|n| divide(n, 27).unwrap()).collect())
+   
+    // let mut divided_numbers: Vec<i32> = Vec::new();
+    // for result in division_results {
+    //      match result {
+    //         Ok(quotient) => divided_numbers.push(quotient),
+    //         _ => continue 
+    //      } 
+    // }
+    // if divided_numbers.is_empty() {
+    //     ()
+    // }
+    // Ok(divided_numbers)
 }
 
 // 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));
+    numbers.into_iter().map(|n| divide(n, 27)).collect()
+    // let mut divided_numbers: Vec<Result<i32, DivisionError>> = Vec::new();
+//     for result in division_results {
+//         match result {
+//            Ok(_) => divided_numbers.push(result),
+//            _ => continue 
+//         } 
+//    }
+//    division_results.for_each(|)
+//    divided_numbers
 }
 
 #[cfg(test)]
diff --git a/exercises/iterators/iterators4.rs b/exercises/iterators/iterators4.rs
index a02470ec..f49d6bae 100644
--- a/exercises/iterators/iterators4.rs
+++ b/exercises/iterators/iterators4.rs
@@ -1,9 +1,15 @@
 // iterators4.rs
 // Execute `rustlings hint iterators4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub fn factorial(num: u64) -> u64 {
+    // let mut product: u64 = 1;
+    // for i in 2..num+1 {
+    //     product *= i;
+    // }
+    // product
+        (2..num+1).into_iter().fold(1, |acc, x| x * acc)
+    
     // Complete this function to return the factorial of num
     // Do not use:
     // - return
diff --git a/exercises/iterators/iterators5.rs b/exercises/iterators/iterators5.rs
index 0593d123..f2241c76 100644
--- a/exercises/iterators/iterators5.rs
+++ b/exercises/iterators/iterators5.rs
@@ -10,7 +10,6 @@
 //
 // Make the code compile and the tests pass.
 
-// I AM NOT DONE
 
 use std::collections::HashMap;
 
@@ -34,7 +33,8 @@ 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 count = 0;
+    map.into_iter().filter_map(|(_, progress)| progress.eq(&value).then_some(value)).count()
 }
 
 fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
@@ -53,7 +53,8 @@ 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.into_iter().fold(0, |acc, map| acc + count_iterator(map, value))
 }
 
 #[cfg(test)]
diff --git a/exercises/lifetimes/lifetimes1.rs b/exercises/lifetimes/lifetimes1.rs
index 0236470d..bd39d98d 100644
--- a/exercises/lifetimes/lifetimes1.rs
+++ b/exercises/lifetimes/lifetimes1.rs
@@ -7,9 +7,8 @@
 //
 // Execute `rustlings hint lifetimes1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT 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 {
diff --git a/exercises/lifetimes/lifetimes2.rs b/exercises/lifetimes/lifetimes2.rs
index b48feabc..8e8c16f1 100644
--- a/exercises/lifetimes/lifetimes2.rs
+++ b/exercises/lifetimes/lifetimes2.rs
@@ -6,8 +6,6 @@
 //
 // Execute `rustlings hint lifetimes2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
     if x.len() > y.len() {
         x
@@ -19,9 +17,9 @@ 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");
         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..e28c59e8 100644
--- a/exercises/lifetimes/lifetimes3.rs
+++ b/exercises/lifetimes/lifetimes3.rs
@@ -4,11 +4,10 @@
 //
 // Execute `rustlings hint lifetimes3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
-struct Book {
-    author: &str,
-    title: &str,
+struct Book<'a> {
+    author: &'a str,
+    title: &'a str,
 }
 
 fn main() {
diff --git a/exercises/modules/modules1.rs b/exercises/modules/modules1.rs
index 8dd0e402..593b1171 100644
--- a/exercises/modules/modules1.rs
+++ b/exercises/modules/modules1.rs
@@ -1,7 +1,6 @@
 // modules1.rs
 // Execute `rustlings hint modules1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 mod sausage_factory {
     // Don't let anybody outside of this module see this!
@@ -9,7 +8,7 @@ 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..7c026b93 100644
--- a/exercises/modules/modules2.rs
+++ b/exercises/modules/modules2.rs
@@ -3,12 +3,11 @@
 // '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
 
-mod delicious_snacks {
+pub 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";
@@ -21,6 +20,7 @@ mod delicious_snacks {
     }
 }
 
+
 fn main() {
     println!(
         "favorite snacks: {} and {}",
diff --git a/exercises/modules/modules3.rs b/exercises/modules/modules3.rs
index 35e07990..181d5a35 100644
--- a/exercises/modules/modules3.rs
+++ b/exercises/modules/modules3.rs
@@ -5,10 +5,9 @@
 // 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
 
 // TODO: Complete this use statement
-use ???
+use std::time::{SystemTime, UNIX_EPOCH};
 
 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..2c2c3715 100644
--- a/exercises/move_semantics/move_semantics1.rs
+++ b/exercises/move_semantics/move_semantics1.rs
@@ -1,12 +1,12 @@
 // move_semantics1.rs
 // Execute `rustlings hint move_semantics1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT 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);
 
diff --git a/exercises/move_semantics/move_semantics2.rs b/exercises/move_semantics/move_semantics2.rs
index 64870850..11412280 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
+
 
 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<i32> = vec.to_vec();
 
     vec.push(22);
     vec.push(44);
diff --git a/exercises/move_semantics/move_semantics3.rs b/exercises/move_semantics/move_semantics3.rs
index eaa30e33..d48492ab 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
+
 
 fn main() {
-    let vec0 = Vec::new();
+    let mut vec0 = 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..b37cdc1b 100644
--- a/exercises/move_semantics/move_semantics4.rs
+++ b/exercises/move_semantics/move_semantics4.rs
@@ -4,12 +4,11 @@
 // function.
 // Execute `rustlings hint move_semantics4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT 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 +19,7 @@ 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::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..c570e1dc 100644
--- a/exercises/move_semantics/move_semantics5.rs
+++ b/exercises/move_semantics/move_semantics5.rs
@@ -3,13 +3,12 @@
 // 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
 
 fn main() {
     let mut x = 100;
     let y = &mut x;
-    let z = &mut x;
     *y += 100;
+    let z = &mut x;
     *z += 1000;
     assert_eq!(x, 1200);
 }
diff --git a/exercises/move_semantics/move_semantics6.rs b/exercises/move_semantics/move_semantics6.rs
index eb52a848..fcef1c38 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
+
 
 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 {
-    data.chars().last().unwrap()
+fn get_char(data: &String) -> char {
+    data.to_string().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 1f891b0e..10f7279a 100644
--- a/exercises/options/options1.rs
+++ b/exercises/options/options1.rs
@@ -1,7 +1,6 @@
 // options1.rs
 // Execute `rustlings hint options1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 // 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 +9,13 @@ fn maybe_icecream(time_of_day: u16) -> Option<u16> {
     // We use the 24-hour system here, so 10PM is a value of 22 and 12AM is a value of 0
     // The Option output should gracefully handle cases where time_of_day > 23.
     // TODO: Complete the function body - remember to return an Option!
-    ???
+    if time_of_day < 22 {
+        Some(5)
+    } else if time_of_day >  23 {
+        None
+    } else {
+        Some(0)
+    }
 }
 
 #[cfg(test)]
@@ -30,6 +35,6 @@ 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);
+        assert_eq!(icecreams.unwrap(), 5);
     }
 }
diff --git a/exercises/options/options2.rs b/exercises/options/options2.rs
index 4e36443f..d1e8a4db 100644
--- a/exercises/options/options2.rs
+++ b/exercises/options/options2.rs
@@ -1,7 +1,6 @@
 // options2.rs
 // Execute `rustlings hint options2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[cfg(test)]
 mod tests {
@@ -11,7 +10,7 @@ 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);
         }
     }
@@ -26,7 +25,7 @@ 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..040e8141 100644
--- a/exercises/options/options3.rs
+++ b/exercises/options/options3.rs
@@ -1,7 +1,6 @@
 // options3.rs
 // Execute `rustlings hint options3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 struct Point {
     x: i32,
@@ -11,7 +10,7 @@ struct Point {
 fn main() {
     let y: Option<Point> = Some(Point { x: 100, y: 200 });
 
-    match y {
+    match &y {
         Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y),
         _ => println!("no match"),
     }
diff --git a/exercises/primitive_types/primitive_types1.rs b/exercises/primitive_types/primitive_types1.rs
index 09121392..82c797e6 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
+
 
 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 = !is_morning;
     if is_evening {
         println!("Good evening!");
     }
diff --git a/exercises/primitive_types/primitive_types2.rs b/exercises/primitive_types/primitive_types2.rs
index 8730baab..2e2aa5f9 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
+
 
 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 = '&';
     // 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..e9c546a6 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
+
 
 fn main() {
-    let a = ???
+    let a = [1..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..3567b6fb 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
+
 
 #[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..f3ecd428 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
+
 
 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..710113eb 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
+
 
 #[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..c2a3d34e 100644
--- a/exercises/quiz1.rs
+++ b/exercises/quiz1.rs
@@ -10,8 +10,14 @@
 // Write a function that calculates the price of an order of apples given
 // the quantity bought. No hints this time!
 
-// I AM NOT DONE
 
+
+fn calculate_price_of_apples(num_apples_bought:i32) -> i32 {
+    let mut price: i32;
+    if num_apples_bought > 40 {price = 1;}
+    else {price = 2;}
+    num_apples_bought * price
+}
 // Put your function here!
 // fn calculate_price_of_apples {
 
diff --git a/exercises/quiz2.rs b/exercises/quiz2.rs
index 5c42dae0..edd135db 100644
--- a/exercises/quiz2.rs
+++ b/exercises/quiz2.rs
@@ -18,7 +18,6 @@
 // - The output element is going to be a Vector of strings.
 // No hints this time!
 
-// I AM NOT DONE
 
 pub enum Command {
     Uppercase,
@@ -30,11 +29,16 @@ 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![];
         for (string, command) in input.iter() {
-            // TODO: Complete the function body. You can do it!
+            match command {
+                Command::Uppercase => output.push(string.to_uppercase().to_string()),
+                Command::Trim => output.push(string.trim().to_string()),
+                Command::Append(n) => output.push(
+                    string.to_string() + &"bar".repeat(*n)),
+            }
         }
         output
     }
@@ -43,7 +47,7 @@ mod my_module {
 #[cfg(test)]
 mod tests {
     // TODO: What do we need 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..79799bd5 100644
--- a/exercises/quiz3.rs
+++ b/exercises/quiz3.rs
@@ -14,21 +14,28 @@
 
 // Execute `rustlings hint quiz3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+use std::fmt::Display;
 
-pub struct ReportCard {
-    pub grade: f32,
+// pub enum Grade {
+//     letter_grade: String,
+//     number_grade: u8,
+// }
+
+pub struct ReportCard<G: Display> {
+    pub grade: G,
     pub student_name: String,
     pub student_age: u8,
 }
 
-impl ReportCard {
+impl <G: Display> ReportCard <G> {
     pub fn print(&self) -> String {
         format!("{} ({}) - achieved a grade of {}",
             &self.student_name, &self.student_age, &self.grade)
     }
 }
 
+
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -50,7 +57,7 @@ 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/strings/strings1.rs b/exercises/strings/strings1.rs
index 0de86a1d..988a3f45 100644
--- a/exercises/strings/strings1.rs
+++ b/exercises/strings/strings1.rs
@@ -2,7 +2,6 @@
 // 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
 
 fn main() {
     let answer = current_favorite_color();
@@ -10,5 +9,5 @@ fn main() {
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    "blue".to_string()
 }
diff --git a/exercises/strings/strings2.rs b/exercises/strings/strings2.rs
index 0c48ec95..a9bd67a7 100644
--- a/exercises/strings/strings2.rs
+++ b/exercises/strings/strings2.rs
@@ -2,11 +2,10 @@
 // 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
 
 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..c24820b8 100644
--- a/exercises/strings/strings3.rs
+++ b/exercises/strings/strings3.rs
@@ -1,21 +1,22 @@
 // strings3.rs
 // Execute `rustlings hint strings3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn trim_me(input: &str) -> String {
     // TODO: Remove whitespace from both ends of a string!
-    ???
+    input.trim().to_string()
 }
 
 fn compose_me(input: &str) -> String {
     // TODO: Add " world!" to the string! There's multiple ways to do this!
-    ???
+    let mut composed_string= String::from(input);
+    composed_string.push_str(" world!");
+    composed_string
 }
 
 fn replace_me(input: &str) -> String {
     // TODO: Replace "cars" in the string with "balloons"!
-    ???
+    input.replace("cars", "balloons").to_string()
 }
 
 #[cfg(test)]
diff --git a/exercises/strings/strings4.rs b/exercises/strings/strings4.rs
index c410b562..bb0c6745 100644
--- a/exercises/strings/strings4.rs
+++ b/exercises/strings/strings4.rs
@@ -6,7 +6,6 @@
 // before the parentheses on each line. If you're right, it will compile!
 // No hints this time!
 
-// I AM NOT DONE
 
 fn string_slice(arg: &str) {
     println!("{}", arg);
@@ -16,14 +15,14 @@ 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_slice("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..7df70914 100644
--- a/exercises/structs/structs1.rs
+++ b/exercises/structs/structs1.rs
@@ -2,13 +2,20 @@
 // 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
+
 
 struct ColorClassicStruct {
-    // TODO: Something goes here
+    red:usize,
+    green:usize,
+    blue:usize,
 }
 
-struct ColorTupleStruct(/* TODO: Something goes here */);
+impl ColorClassicStruct {
+    fn new(red:usize, green:usize, blue:usize) -> ColorClassicStruct {
+        ColorClassicStruct { red: (red), green: (green), blue: (blue) }
+    }
+}
+struct ColorTupleStruct(i32, i32, i32);
 
 #[derive(Debug)]
 struct UnitLikeStruct;
@@ -20,7 +27,7 @@ mod tests {
     #[test]
     fn classic_c_structs() {
         // TODO: Instantiate a classic c struct!
-        // let green =
+        let green = ColorClassicStruct::new(0,255,0);
 
         assert_eq!(green.red, 0);
         assert_eq!(green.green, 255);
@@ -30,7 +37,7 @@ 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 +47,7 @@ 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..098c109f 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
+
 
 #[derive(Debug)]
 struct Order {
@@ -35,7 +35,11 @@ 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 = "Hacker in Rust".to_string();
+        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 3536a457..c438dc50 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
+
 
 #[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 {
+        self.weight_in_grams * cents_per_gram
     }
 }
 
diff --git a/exercises/tests/tests1.rs b/exercises/tests/tests1.rs
index 8b6ea374..34baba7f 100644
--- a/exercises/tests/tests1.rs
+++ b/exercises/tests/tests1.rs
@@ -7,12 +7,11 @@
 // pass! Make the test fail!
 // Execute `rustlings hint tests1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT 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..d47d45bf 100644
--- a/exercises/tests/tests2.rs
+++ b/exercises/tests/tests2.rs
@@ -3,12 +3,11 @@
 // pass! Make the test fail!
 // Execute `rustlings hint tests2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[cfg(test)]
 mod tests {
     #[test]
     fn you_can_assert_eq() {
-        assert_eq!();
+        assert_eq!(4,4);
     }
 }
diff --git a/exercises/tests/tests3.rs b/exercises/tests/tests3.rs
index 196a81a0..f42f7515 100644
--- a/exercises/tests/tests3.rs
+++ b/exercises/tests/tests3.rs
@@ -4,7 +4,6 @@
 // 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
 
 pub fn is_even(num: i32) -> bool {
     num % 2 == 0
@@ -16,11 +15,11 @@ mod tests {
 
     #[test]
     fn is_true_when_even() {
-        assert!();
+        assert!(is_even(2));
     }
 
     #[test]
     fn is_false_when_odd() {
-        assert!();
+        assert!(!is_even(5));
     }
 }
diff --git a/exercises/threads/threads1.rs b/exercises/threads/threads1.rs
index d6376db2..238312cd 100644
--- a/exercises/threads/threads1.rs
+++ b/exercises/threads/threads1.rs
@@ -6,7 +6,6 @@
 // The program should wait until all the spawned threads have finished and
 // should collect their return values into a vector.
 
-// I AM NOT DONE
 
 use std::thread;
 use std::time::{Duration, Instant};
@@ -24,7 +23,7 @@ fn main() {
 
     let mut results: Vec<u128> = vec![];
     for handle in handles {
-        // TODO: a struct is returned from thread::spawn, can you use it?
+        results.push(handle.join().unwrap());
     }
 
     if results.len() != 10 {
diff --git a/exercises/threads/threads2.rs b/exercises/threads/threads2.rs
index ada3d14a..3f8b039c 100644
--- a/exercises/threads/threads2.rs
+++ b/exercises/threads/threads2.rs
@@ -3,9 +3,8 @@
 // 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
 
-use std::sync::Arc;
+use std::sync::{Arc, Mutex};
 use std::thread;
 use std::time::Duration;
 
@@ -14,14 +13,15 @@ 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 = Arc::clone(&status);
         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;
+            status_shared.lock().unwrap().jobs_completed += 1;
+            
         });
         handles.push(handle);
     }
@@ -29,6 +29,6 @@ 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/traits/traits1.rs b/exercises/traits/traits1.rs
index f5320a5a..16189248 100644
--- a/exercises/traits/traits1.rs
+++ b/exercises/traits/traits1.rs
@@ -9,14 +9,16 @@
 // implementing this trait.
 // Execute `rustlings hint traits1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+
 
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
 impl AppendBar for String {
-    // TODO: Implement `AppendBar` for type `String`.
+    fn append_bar(self) -> Self {
+        self + &"Bar".to_string()
+    }
 }
 
 fn main() {
diff --git a/exercises/traits/traits2.rs b/exercises/traits/traits2.rs
index 288b4983..bb9690b8 100644
--- a/exercises/traits/traits2.rs
+++ b/exercises/traits/traits2.rs
@@ -11,13 +11,18 @@
 // you can do this!
 // Execute `rustlings hint traits2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
-// TODO: Implement trait `AppendBar` for a vector of strings.
+impl AppendBar for Vec<String> {
+    fn append_bar(self) -> Self {
+        let mut new_vec: Vec<String> = self;
+        new_vec.push(String::from("Bar"));
+        new_vec
+    } 
+}
 
 #[cfg(test)]
 mod tests {
diff --git a/exercises/traits/traits3.rs b/exercises/traits/traits3.rs
index 6d2fd6c3..be56000c 100644
--- a/exercises/traits/traits3.rs
+++ b/exercises/traits/traits3.rs
@@ -7,10 +7,11 @@
 // 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
 
 pub trait Licensed {
-    fn licensing_info(&self) -> String;
+    fn licensing_info(&self) -> String {
+        String::from("Some information")
+    }
 }
 
 struct SomeSoftware {
diff --git a/exercises/traits/traits4.rs b/exercises/traits/traits4.rs
index 6b541665..8168e16f 100644
--- a/exercises/traits/traits4.rs
+++ b/exercises/traits/traits4.rs
@@ -4,7 +4,6 @@
 // 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
 
 pub trait Licensed {
     fn licensing_info(&self) -> String {
@@ -20,7 +19,17 @@ 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<T,S>(software: T, software_two: S) -> bool 
+//     where 
+//         T: Licensed,
+//         S: Licensed
+//     {software.licensing_info() == software_two.licensing_info()
+// }
+// fn compare_license_types(software: (impl Licensed), software_two: (impl Licensed)) -> bool 
+    
+//     {software.licensing_info() == software_two.licensing_info()
+// }
+fn compare_license_types<T: Licensed,S: Licensed>(software: T, software_two: S) -> bool {
     software.licensing_info() == software_two.licensing_info()
 }
 
diff --git a/exercises/traits/traits5.rs b/exercises/traits/traits5.rs
index 0fbca28a..e67f6d17 100644
--- a/exercises/traits/traits5.rs
+++ b/exercises/traits/traits5.rs
@@ -4,7 +4,6 @@
 // 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
 
 pub trait SomeTrait {
     fn some_function(&self) -> bool {
@@ -27,7 +26,7 @@ impl SomeTrait for OtherStruct {}
 impl OtherTrait for OtherStruct {}
 
 // YOU MAY ONLY CHANGE THE NEXT LINE
-fn some_func(item: ??) -> bool {
+fn some_func<T:SomeTrait+OtherTrait>(item: T) -> bool {
     item.some_function() && item.other_function()
 }
 
diff --git a/exercises/variables/variables1.rs b/exercises/variables/variables1.rs
index f4d182ac..14758e98 100644
--- a/exercises/variables/variables1.rs
+++ b/exercises/variables/variables1.rs
@@ -2,9 +2,9 @@
 // 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..548c2313 100644
--- a/exercises/variables/variables2.rs
+++ b/exercises/variables/variables2.rs
@@ -1,10 +1,10 @@
 // variables2.rs
 // Execute `rustlings hint variables2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+
 
 fn main() {
-    let x;
+    let x = 10;
     if x == 10 {
         println!("x is ten!");
     } else {
diff --git a/exercises/variables/variables3.rs b/exercises/variables/variables3.rs
index 819b1bc7..ab5da21c 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 = 7;
     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..2ac6b3d5 100644
--- a/exercises/variables/variables5.rs
+++ b/exercises/variables/variables5.rs
@@ -1,11 +1,12 @@
 // variables5.rs
 // Execute `rustlings hint variables5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+
 
 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
-    println!("Number plus two is : {}", number + 2);
+    {   let number: i32 = 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..e7ea1aa6 100644
--- a/exercises/variables/variables6.rs
+++ b/exercises/variables/variables6.rs
@@ -1,9 +1,8 @@
 // variables6.rs
 // Execute `rustlings hint variables6` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
-const NUMBER = 3;
+const NUMBER: usize = 3;
 fn main() {
     println!("Number {}", NUMBER);
 }
diff --git a/exercises/vecs/vecs1.rs b/exercises/vecs/vecs1.rs
index 4e8c4cbb..0a906343 100644
--- a/exercises/vecs/vecs1.rs
+++ b/exercises/vecs/vecs1.rs
@@ -4,11 +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
+
 
 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!(a[0], a[1], a[2], a[3]); // 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 1ea26071..d3de5b55 100644
--- a/exercises/vecs/vecs2.rs
+++ b/exercises/vecs/vecs2.rs
@@ -6,13 +6,13 @@
 //
 // Execute `rustlings hint vecs2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+
 
 fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
     for element in v.iter_mut() {
         // TODO: Fill this up so that each element in the Vec `v` is
         // multiplied by 2.
-        ???
+        *element = *element * 2;
     }
 
     // At this point, `v` should be equal to [4, 8, 12, 16, 20].
@@ -23,7 +23,7 @@ fn vec_map(v: &Vec<i32>) -> Vec<i32> {
     v.iter().map(|element| {
         // TODO: Do the same thing as above - but instead of mutating the
         // Vec, you can just return the new number!
-        ???
+        *element * 2
     }).collect()
 }
 
diff --git a/rustlings b/rustlings
new file mode 160000
index 00000000..7f1754ec
--- /dev/null
+++ b/rustlings
@@ -0,0 +1 @@
+Subproject commit 7f1754ecc5690f31db4aff38eef2bf30e2aec525