diff --git a/exercises/enums/enums1.rs b/exercises/enums/enums1.rs
index 511ba740..eb718a7a 100644
--- a/exercises/enums/enums1.rs
+++ b/exercises/enums/enums1.rs
@@ -1,11 +1,13 @@
 // 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..1ef0698d 100644
--- a/exercises/enums/enums2.rs
+++ b/exercises/enums/enums2.rs
@@ -1,11 +1,13 @@
 // 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: i32, y: i32 },
+    Echo(String),
+    ChangeColor(i32, i32, i32),
+    Quit
 }
 
 impl Message {
diff --git a/exercises/enums/enums3.rs b/exercises/enums/enums3.rs
index a2a9d586..6625c5a1 100644
--- a/exercises/enums/enums3.rs
+++ b/exercises/enums/enums3.rs
@@ -2,10 +2,12 @@
 // 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
-
 enum Message {
     // TODO: implement the message variant types based on their usage below
+    ChangeColor(u8, u8, u8),
+    Echo(String),
+    Move(Point),
+    Quit
 }
 
 struct Point {
@@ -39,6 +41,13 @@ 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::Quit => self.quit(),
+            Message::Move(point) => self.move_position(point),
+            Message::ChangeColor(r, g, b) => self.change_color((r, g, b)),
+            Message::Echo(message) => self.echo(message),
+
+        }
     }
 }
 
diff --git a/exercises/error_handling/errors1.rs b/exercises/error_handling/errors1.rs
index bcee9723..7daa4552 100644
--- a/exercises/error_handling/errors1.rs
+++ b/exercises/error_handling/errors1.rs
@@ -5,14 +5,12 @@
 // 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(String::from("`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 6971fcfb..276f3684 100644
--- a/exercises/error_handling/errors2.rs
+++ b/exercises/error_handling/errors2.rs
@@ -17,14 +17,12 @@
 // 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>();
+    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..8435abcc 100644
--- a/exercises/error_handling/errors3.rs
+++ b/exercises/error_handling/errors3.rs
@@ -4,11 +4,9 @@
 // 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;
 
-fn main() {
+fn main() -> Result<(), ParseIntError>{
     let mut tokens = 100;
     let pretend_user_input = "8";
 
@@ -20,6 +18,8 @@ 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..3d13b78b 100644
--- a/exercises/error_handling/errors4.rs
+++ b/exercises/error_handling/errors4.rs
@@ -1,8 +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 +13,14 @@ 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 > 0 {
+            Ok(PositiveNonzeroInteger(value as u64))
+        } else if value == 0 {
+            Err(CreationError::Zero)
+        } else {
+            Err(CreationError::Negative)
+
+        }
     }
 }
 
diff --git a/exercises/error_handling/errors5.rs b/exercises/error_handling/errors5.rs
index eb5506cb..7a9a85b6 100644
--- a/exercises/error_handling/errors5.rs
+++ b/exercises/error_handling/errors5.rs
@@ -16,14 +16,12 @@
 
 // Execute `rustlings hint errors5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT 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 8097b490..f9d19e2c 100644
--- a/exercises/error_handling/errors6.rs
+++ b/exercises/error_handling/errors6.rs
@@ -8,8 +8,6 @@
 
 // Execute `rustlings hint errors6` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::num::ParseIntError;
 
 // This is a custom error type that we will be using in `parse_pos_nonzero()`.
@@ -23,6 +21,9 @@ impl ParsePosNonzeroError {
     fn from_creation(err: CreationError) -> ParsePosNonzeroError {
         ParsePosNonzeroError::Creation(err)
     }
+    fn from_parseint(err: ParseIntError) -> ParsePosNonzeroError {
+        ParsePosNonzeroError::ParseInt(err)
+    }
     // TODO: add another error conversion function here.
     // fn from_parseint...
 }
@@ -30,7 +31,7 @@ impl ParsePosNonzeroError {
 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();
+    let x: i64 = s.parse().map_err(ParsePosNonzeroError::from_parseint)?;
     PositiveNonzeroInteger::new(x).map_err(ParsePosNonzeroError::from_creation)
 }
 
diff --git a/exercises/functions/functions1.rs b/exercises/functions/functions1.rs
index 03d8af70..6a2f1d7e 100644
--- a/exercises/functions/functions1.rs
+++ b/exercises/functions/functions1.rs
@@ -1,7 +1,8 @@
 // functions1.rs
 // Execute `rustlings hint functions1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+fn call_me() {
+}
 
 fn main() {
     call_me();
diff --git a/exercises/functions/functions2.rs b/exercises/functions/functions2.rs
index 7d40a578..5a51bdfb 100644
--- a/exercises/functions/functions2.rs
+++ b/exercises/functions/functions2.rs
@@ -1,13 +1,11 @@
 // 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..3ea3a815 100644
--- a/exercises/functions/functions3.rs
+++ b/exercises/functions/functions3.rs
@@ -1,10 +1,8 @@
 // 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(32);
 }
 
 fn call_me(num: u32) {
diff --git a/exercises/functions/functions4.rs b/exercises/functions/functions4.rs
index 65d5be4f..b16640f5 100644
--- a/exercises/functions/functions4.rs
+++ b/exercises/functions/functions4.rs
@@ -7,14 +7,12 @@
 // 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: u32) -> u32 {
     if is_even(price) {
         price - 10
     } else {
@@ -22,6 +20,6 @@ fn sale_price(price: i32) -> {
     }
 }
 
-fn is_even(num: i32) -> bool {
+fn is_even(num: u32) -> bool {
     num % 2 == 0
 }
diff --git a/exercises/functions/functions5.rs b/exercises/functions/functions5.rs
index 5d762961..ee8210ab 100644
--- a/exercises/functions/functions5.rs
+++ b/exercises/functions/functions5.rs
@@ -1,13 +1,11 @@
 // 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);
     println!("The square of 3 is {}", answer);
 }
 
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }
diff --git a/exercises/generics/generics1.rs b/exercises/generics/generics1.rs
index 4c34ae47..e3ec91aa 100644
--- a/exercises/generics/generics1.rs
+++ b/exercises/generics/generics1.rs
@@ -3,9 +3,7 @@
 
 // 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..ef084440 100644
--- a/exercises/generics/generics2.rs
+++ b/exercises/generics/generics2.rs
@@ -3,14 +3,12 @@
 
 // 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..f53001e6 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(); // TODO: declare your hash map here.
 
     // Two bananas are already given for you :)
+    
     basket.insert(String::from("banana"), 2);
+    basket.insert(String::from("mango"), 2);
+    basket.insert(String::from("apple"), 2);
 
     // TODO: Put more fruits in your basket here.
 
diff --git a/exercises/hashmaps/hashmaps2.rs b/exercises/hashmaps/hashmaps2.rs
index a4f069a8..d9d90687 100644
--- a/exercises/hashmaps/hashmaps2.rs
+++ b/exercises/hashmaps/hashmaps2.rs
@@ -13,8 +13,6 @@
 //
 // Execute `rustlings hint hashmaps2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 #[derive(Hash, PartialEq, Eq)]
@@ -39,6 +37,7 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
         // TODO: Insert new fruits if they are not already present in the basket.
         // Note that you are not allowed to put any type of fruit that's already
         // present!
+        basket.entry(fruit).or_insert(10);
     }
 }
 
diff --git a/exercises/hashmaps/hashmaps3.rs b/exercises/hashmaps/hashmaps3.rs
index ad3baa68..1fae9533 100644
--- a/exercises/hashmaps/hashmaps3.rs
+++ b/exercises/hashmaps/hashmaps3.rs
@@ -14,8 +14,6 @@
 
 // Execute `rustlings hint hashmaps3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 // A structure to store team name and its goal details.
@@ -40,6 +38,26 @@ fn build_scores_table(results: String) -> HashMap<String, Team> {
         // 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.
+        let initial_team_1 = Team {
+            name: team_1_name.clone(),
+            goals_scored: team_1_score,
+            goals_conceded: team_2_score,
+        };
+        let initial_team_2 = Team {
+            name: team_2_name.clone(),
+            goals_scored: team_2_score,
+            goals_conceded: team_1_score,
+        };
+        scores.entry(team_1_name).and_modify(|t| {
+            t.goals_scored += team_1_score;
+            t.goals_conceded += team_2_score;
+        }).or_insert(initial_team_1);;
+        scores.entry(team_2_name).and_modify(|t| {
+            t.goals_scored += team_2_score;
+            t.goals_conceded += team_1_score;
+        }).or_insert(initial_team_2);;
+        // scores.insert(team_1_name, team_1);
+        // scores.insert(team_2_name, team_2);
     }
     scores
 }
diff --git a/exercises/if/if1.rs b/exercises/if/if1.rs
index 587e03f8..3277bda8 100644
--- a/exercises/if/if1.rs
+++ b/exercises/if/if1.rs
@@ -1,13 +1,17 @@
 // 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 {
+        b
+    }
 }
 
 // Don't mind this for now :)
diff --git a/exercises/if/if2.rs b/exercises/if/if2.rs
index effddbb6..129a4a25 100644
--- a/exercises/if/if2.rs
+++ b/exercises/if/if2.rs
@@ -4,13 +4,13 @@
 // 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 if fizzish == "fuzz" {
+        "bar"
     } else {
-        1
+        "baz"
     }
 }
 
diff --git a/exercises/modules/modules1.rs b/exercises/modules/modules1.rs
index 8dd0e402..09d5ab3e 100644
--- a/exercises/modules/modules1.rs
+++ b/exercises/modules/modules1.rs
@@ -1,15 +1,13 @@
 // 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!
     fn get_secret_recipe() -> String {
         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..65ea5a83 100644
--- a/exercises/modules/modules2.rs
+++ b/exercises/modules/modules2.rs
@@ -3,12 +3,10 @@
 // '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 {
     // 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";
diff --git a/exercises/modules/modules3.rs b/exercises/modules/modules3.rs
index 35e07990..399c257f 100644
--- a/exercises/modules/modules3.rs
+++ b/exercises/modules/modules3.rs
@@ -5,10 +5,8 @@
 // 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::*;
 
 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..b8c388b1 100644
--- a/exercises/move_semantics/move_semantics1.rs
+++ b/exercises/move_semantics/move_semantics1.rs
@@ -1,12 +1,10 @@
 // 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 vec0: Vec<i32> = 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 93bb82ef..4939ee6b 100644
--- a/exercises/move_semantics/move_semantics2.rs
+++ b/exercises/move_semantics/move_semantics2.rs
@@ -5,25 +5,21 @@
 // vec0 has length 3 content `[22, 44, 66]`
 // vec1 has length 4 content `[22, 44, 66, 88]`
 
-// I AM NOT DONE
-
 fn main() {
-    let vec0 = Vec::new();
+    let mut vec0: Vec<i32> = Vec::new();
 
     // Do not move the following line!
-    let mut vec1 = fill_vec(vec0);
+    fill_vec(&mut vec0);
 
     // Do not change the following line!
     println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0);
 
-    vec1.push(88);
+    vec0.push(88);
 
-    println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
+    println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0);
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
-    let mut vec = vec;
-
+fn fill_vec(vec: &mut Vec<i32>) -> &Vec<i32> {
     vec.push(22);
     vec.push(44);
     vec.push(66);
diff --git a/exercises/move_semantics/move_semantics3.rs b/exercises/move_semantics/move_semantics3.rs
index eaa30e33..dbc49b1f 100644
--- a/exercises/move_semantics/move_semantics3.rs
+++ b/exercises/move_semantics/move_semantics3.rs
@@ -3,12 +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);
+    let mut vec1 = fill_vec(&mut vec0);
 
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 
@@ -17,7 +15,7 @@ fn main() {
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
+fn fill_vec(vec: &mut Vec<i32>) -> &mut 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..129e754c 100644
--- a/exercises/move_semantics/move_semantics4.rs
+++ b/exercises/move_semantics/move_semantics4.rs
@@ -4,12 +4,8 @@
 // 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 mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec();
 
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 
@@ -20,7 +16,7 @@ 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..ab04f4c7 100644
--- a/exercises/move_semantics/move_semantics5.rs
+++ b/exercises/move_semantics/move_semantics5.rs
@@ -3,13 +3,11 @@
 // 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..055ea5bf 100644
--- a/exercises/move_semantics/move_semantics6.rs
+++ b/exercises/move_semantics/move_semantics6.rs
@@ -2,24 +2,22 @@
 // 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 {
+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 1f891b0e..b5f73a85 100644
--- a/exercises/options/options1.rs
+++ b/exercises/options/options1.rs
@@ -1,8 +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
 // all, so there'll be no more left :(
@@ -10,7 +8,13 @@ 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 < 1 || time_of_day > 23 {
+        None
+    } else if time_of_day >= 22 {
+        Some(0)
+    } else {
+        Some(5)
+    }
 }
 
 #[cfg(test)]
@@ -29,7 +33,7 @@ mod tests {
     #[test]
     fn raw_value() {
         // TODO: Fix this test. How do you get at the value contained in the Option?
-        let icecreams = maybe_icecream(12);
+        let icecreams = maybe_icecream(12).unwrap();
         assert_eq!(icecreams, 5);
     }
 }
diff --git a/exercises/options/options2.rs b/exercises/options/options2.rs
index 4e36443f..c9be5fd4 100644
--- a/exercises/options/options2.rs
+++ b/exercises/options/options2.rs
@@ -1,8 +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 {
     #[test]
@@ -11,7 +9,7 @@ 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 +24,7 @@ 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(integer) = optional_integers.pop().flatten() {
             assert_eq!(integer, range);
             range -= 1;
         }
diff --git a/exercises/options/options3.rs b/exercises/options/options3.rs
index 3f995c52..1dd0b374 100644
--- a/exercises/options/options3.rs
+++ b/exercises/options/options3.rs
@@ -1,8 +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,
     y: i32,
@@ -12,7 +10,7 @@ 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..56341acb 100644
--- a/exercises/primitive_types/primitive_types1.rs
+++ b/exercises/primitive_types/primitive_types1.rs
@@ -2,8 +2,6 @@
 // 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 +10,7 @@ fn main() {
         println!("Good morning!");
     }
 
-    let // Finish the rest of this line like the example! Or make it be false!
+    let is_evening: bool = true; // 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..c42db979 100644
--- a/exercises/primitive_types/primitive_types2.rs
+++ b/exercises/primitive_types/primitive_types2.rs
@@ -2,8 +2,6 @@
 // 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 +16,7 @@ fn main() {
         println!("Neither alphabetic nor numeric!");
     }
 
-    let // Finish this line like the example! What's your favorite character?
+    let your_character = 'm'; // 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..d740e41a 100644
--- a/exercises/primitive_types/primitive_types3.rs
+++ b/exercises/primitive_types/primitive_types3.rs
@@ -2,10 +2,8 @@
 // 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 = ["Are we there yet?"; 10];
 
     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..e3371784 100644
--- a/exercises/primitive_types/primitive_types4.rs
+++ b/exercises/primitive_types/primitive_types4.rs
@@ -2,13 +2,11 @@
 // 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..5cba3c15 100644
--- a/exercises/primitive_types/primitive_types5.rs
+++ b/exercises/primitive_types/primitive_types5.rs
@@ -2,11 +2,9 @@
 // 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..695d2815 100644
--- a/exercises/primitive_types/primitive_types6.rs
+++ b/exercises/primitive_types/primitive_types6.rs
@@ -3,13 +3,11 @@
 // 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..0cf11772 100644
--- a/exercises/quiz1.rs
+++ b/exercises/quiz1.rs
@@ -10,10 +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
-
 // Put your function here!
-// fn calculate_price_of_apples {
+fn calculate_price_of_apples(quantity: u32) -> u32 {
+    if quantity > 40 {
+        quantity
+    } else {
+        quantity * 2
+    }
+}
 
 // Don't modify this function!
 #[test]
diff --git a/exercises/quiz2.rs b/exercises/quiz2.rs
index 5c42dae0..e0512dc7 100644
--- a/exercises/quiz2.rs
+++ b/exercises/quiz2.rs
@@ -18,8 +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,
     Trim,
@@ -30,11 +28,19 @@ 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!
+            match command {
+                Command::Uppercase => output.push(string.to_uppercase()),
+                Command::Trim => output.push(string.trim().to_string()),
+                Command::Append(i) => {
+                    let appended_text = string.to_owned() + &"bar".repeat(*i);
+                    output.push(appended_text)
+                },
+            }
         }
         output
     }
@@ -43,7 +49,7 @@ mod my_module {
 #[cfg(test)]
 mod tests {
     // TODO: What do we need to import to have `transformer` in scope?
-    use ???;
+    use crate::my_module::transformer;
     use super::Command;
 
     #[test]
diff --git a/exercises/strings/strings1.rs b/exercises/strings/strings1.rs
index 0de86a1d..1211c9ea 100644
--- a/exercises/strings/strings1.rs
+++ b/exercises/strings/strings1.rs
@@ -2,13 +2,11 @@
 // 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();
     println!("My current favorite color is {}", answer);
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    String::from("blue")
 }
diff --git a/exercises/strings/strings2.rs b/exercises/strings/strings2.rs
index 0c48ec95..22e8986e 100644
--- a/exercises/strings/strings2.rs
+++ b/exercises/strings/strings2.rs
@@ -2,11 +2,9 @@
 // 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..0458e430 100644
--- a/exercises/strings/strings3.rs
+++ b/exercises/strings/strings3.rs
@@ -1,21 +1,20 @@
 // 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!
-    ???
+    // input.to_owned().push_str(" world!")
+    format!("{} world!", input)
 }
 
 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..0205f9c3 100644
--- a/exercises/strings/strings4.rs
+++ b/exercises/strings/strings4.rs
@@ -6,8 +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 +14,14 @@ 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..2c9fbaa1 100644
--- a/exercises/structs/structs1.rs
+++ b/exercises/structs/structs1.rs
@@ -2,13 +2,13 @@
 // 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
+    green: i32,
+    red: i32,
+    blue: i32
 }
 
-struct ColorTupleStruct(/* TODO: Something goes here */);
+struct ColorTupleStruct(i32, i32, i32);
 
 #[derive(Debug)]
 struct UnitLikeStruct;
@@ -20,7 +20,11 @@ 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 +34,7 @@ mod tests {
     #[test]
     fn tuple_structs() {
         // TODO: Instantiate a tuple struct!
-        // let green =
+        let green = ColorTupleStruct(0, 255, 0);
 
         assert_eq!(green.0, 0);
         assert_eq!(green.1, 255);
@@ -40,7 +44,7 @@ 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..5ac07c0b 100644
--- a/exercises/structs/structs2.rs
+++ b/exercises/structs/structs2.rs
@@ -2,8 +2,6 @@
 // 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 {
     name: String,
@@ -35,7 +33,20 @@ 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 your_order = Order {
+        //     name: String::from("Hacker in Rust"),
+        //     year: 2019,
+        //     made_by_phone: false,
+        //     made_by_mobile: false,
+        //     made_by_email: true,
+        //     item_number: 123,
+        //     count: 1,   
+        // };
+        let your_order = Order {
+            name: String::from("Hacker in Rust"),
+            count: 1,
+            ..order_template
+        };
         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..b036947b 100644
--- a/exercises/structs/structs3.rs
+++ b/exercises/structs/structs3.rs
@@ -4,8 +4,6 @@
 // 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 {
     sender_country: String,
@@ -26,12 +24,12 @@ 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
     }
 }
 
@@ -76,7 +74,6 @@ mod tests {
         let cents_per_gram = 3;
 
         let package = Package::new(sender_country, recipient_country, 1500);
-
         assert_eq!(package.get_fees(cents_per_gram), 4500);
         assert_eq!(package.get_fees(cents_per_gram * 2), 9000);
     }
diff --git a/exercises/traits/traits1.rs b/exercises/traits/traits1.rs
index f5320a5a..10f70592 100644
--- a/exercises/traits/traits1.rs
+++ b/exercises/traits/traits1.rs
@@ -9,14 +9,15 @@
 // 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"
+    }
 }
 
 fn main() {
diff --git a/exercises/traits/traits2.rs b/exercises/traits/traits2.rs
index 288b4983..bcd4e1aa 100644
--- a/exercises/traits/traits2.rs
+++ b/exercises/traits/traits2.rs
@@ -18,6 +18,16 @@ trait AppendBar {
 }
 
 // TODO: Implement trait `AppendBar` for a vector of strings.
+impl AppendBar for Vec<String> {
+    fn append_bar(self) -> Self {
+        let mut new_self: Vec<String> = self.clone();
+
+        for mut ele in self {
+            ele = ele + "Bar"
+        }
+        self
+    }
+}
 
 #[cfg(test)]
 mod tests {
diff --git a/exercises/variables/variables3.rs b/exercises/variables/variables3.rs
index 819b1bc7..6a696acb 100644
--- a/exercises/variables/variables3.rs
+++ b/exercises/variables/variables3.rs
@@ -1,9 +1,7 @@
 // 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 = 0;
     println!("Number {}", x);
 }
diff --git a/exercises/variables/variables4.rs b/exercises/variables/variables4.rs
index 54491b0a..8c2ddd6d 100644
--- a/exercises/variables/variables4.rs
+++ b/exercises/variables/variables4.rs
@@ -1,10 +1,8 @@
 // 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..1b9d9f48 100644
--- a/exercises/variables/variables5.rs
+++ b/exercises/variables/variables5.rs
@@ -1,11 +1,9 @@
 // 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
+    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..e8314b28 100644
--- a/exercises/variables/variables6.rs
+++ b/exercises/variables/variables6.rs
@@ -1,9 +1,7 @@
 // variables6.rs
 // Execute `rustlings hint variables6` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
-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..4258d760 100644
--- a/exercises/vecs/vecs1.rs
+++ b/exercises/vecs/vecs1.rs
@@ -4,11 +4,22 @@
 // Make me compile and pass the test!
 // Execute `rustlings hint vecs1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+struct User {
+    active: bool,
+    username: String,
+    email: String,
+    sign_in_count: u64,
+}
 
 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 mut v = vec![10, 20, 30, 40]; // TODO: declare your vector here with the macro for vectors
+    let user1 = User {
+        active: true,
+        email: String::from("someone@example.com"),
+        username: "test".to_string(),
+        sign_in_count: 1,
+    };
 
     (a, v)
 }
diff --git a/exercises/vecs/vecs2.rs b/exercises/vecs/vecs2.rs
index 1ea26071..05f98421 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
-
 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 +21,7 @@ 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()
 }