diff --git a/exercises/collections/hashmap1.rs b/exercises/collections/hashmap1.rs
index b1dc0bb..8fc601b 100644
--- a/exercises/collections/hashmap1.rs
+++ b/exercises/collections/hashmap1.rs
@@ -11,17 +11,16 @@
 // Execute the command `rustlings hint collections3` if you need
 // hints.
 
-// 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("apple"), 2);
+    basket.insert(String::from("cherry"), 3);
 
-    // TODO: Put more fruits in your basket here.
 
     basket
 }
diff --git a/exercises/collections/hashmap2.rs b/exercises/collections/hashmap2.rs
index 7e25be7..634b5d0 100644
--- a/exercises/collections/hashmap2.rs
+++ b/exercises/collections/hashmap2.rs
@@ -12,8 +12,6 @@
 // Execute the command `rustlings hint collections4` if you need
 // hints.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 #[derive(Hash, PartialEq, Eq)]
@@ -35,9 +33,7 @@ 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!
+        basket.entry(fruit).or_insert(1);
     }
 }
 
diff --git a/exercises/collections/vec1.rs b/exercises/collections/vec1.rs
index f6bc837..7016088 100644
--- a/exercises/collections/vec1.rs
+++ b/exercises/collections/vec1.rs
@@ -4,11 +4,9 @@
 // Make me compile and pass the test!
 // Execute the command `rustlings hint collections1` if you need hints.
 
-// 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 = a.to_vec(); // TODO: declare your vector here with the macro for vectors
 
     (a, v)
 }
diff --git a/exercises/collections/vec2.rs b/exercises/collections/vec2.rs
index ec6cfc0..84ee81a 100644
--- a/exercises/collections/vec2.rs
+++ b/exercises/collections/vec2.rs
@@ -7,12 +7,9 @@
 // Execute the command `rustlings hint collections2` if you need
 // hints.
 
-// I AM NOT DONE
-
 fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
     for i in v.iter_mut() {
-        // TODO: Fill this up so that each element in the Vec `v` is
-        // multiplied by 2.
+        *i = *i * 2
     }
 
     // At this point, `v` should be equal to [4, 8, 12, 16, 20].
diff --git a/exercises/enums/enums1.rs b/exercises/enums/enums1.rs
index a2223d3..1654999 100644
--- a/exercises/enums/enums1.rs
+++ b/exercises/enums/enums1.rs
@@ -1,11 +1,12 @@
 // enums1.rs
 // Make me compile! Execute `rustlings hint enums1` for hints!
 
-// 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 ec32d95..5585dc6 100644
--- a/exercises/enums/enums2.rs
+++ b/exercises/enums/enums2.rs
@@ -1,11 +1,12 @@
 // enums2.rs
 // Make me compile! Execute `rustlings hint enums2` for hints!
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 enum Message {
-    // TODO: define the different variants used below
+    Move { x: i32, y: i32 },
+    Echo(String),
+    Quit,
+    ChangeColor(i32, i32, i32)
 }
 
 impl Message {
diff --git a/exercises/enums/enums3.rs b/exercises/enums/enums3.rs
index 178b40c..95814c4 100644
--- a/exercises/enums/enums3.rs
+++ b/exercises/enums/enums3.rs
@@ -1,10 +1,11 @@
 // enums3.rs
 // Address all the TODOs to make the tests pass!
 
-// 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 {
@@ -36,7 +37,12 @@ impl State {
     }
 
     fn process(&mut self, message: Message) {
-        // TODO: create a match expression to process the different message variants
+        match message {
+            Message::ChangeColor(color) => self.change_color(color),
+            Message::Echo(comment) => self.echo(comment),
+            Message::Move(point) => self.move_position(point),
+            Message::Quit => self.quit() 
+        }
     }
 }
 
diff --git a/exercises/modules/modules1.rs b/exercises/modules/modules1.rs
index 812dfee..3af7f48 100644
--- a/exercises/modules/modules1.rs
+++ b/exercises/modules/modules1.rs
@@ -1,10 +1,8 @@
 // modules1.rs
 // Make me compile! Execute `rustlings hint modules1` for hints :)
 
-// I AM NOT DONE
-
 mod sausage_factory {
-    fn make_sausage() {
+    pub fn make_sausage() {
         println!("sausage!");
     }
 }
diff --git a/exercises/modules/modules2.rs b/exercises/modules/modules2.rs
index fde439d..50a3f08 100644
--- a/exercises/modules/modules2.rs
+++ b/exercises/modules/modules2.rs
@@ -1,11 +1,9 @@
 // modules2.rs
 // Make me compile! Execute `rustlings hint modules2` for hints :)
 
-// I AM NOT DONE
-
 mod delicious_snacks {
-    use self::fruits::PEAR as fruit;
-    use self::veggies::CUCUMBER as veggie;
+    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/primitive_types/primitive_types1.rs b/exercises/primitive_types/primitive_types1.rs
index 0912139..715ca72 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 = false;// Finish the rest of this line like the example! Or make it be false!
     if is_evening {
         println!("Good evening!");
     }
diff --git a/exercises/primitive_types/primitive_types2.rs b/exercises/primitive_types/primitive_types2.rs
index 6576a4d..69f6184 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`)
 
@@ -16,7 +14,7 @@ fn main() {
         println!("Neither alphabetic nor numeric!");
     }
 
-    let // Finish this line like the example! What's your favorite character?
+    let your_character = '&';// 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 aaa518b..b44bd52 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` for hints!
 
-// I AM NOT DONE
-
 fn main() {
-    let a = ???
+    let a = ["cool"; 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 10b553e..d773c13 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` for hints!!
 
-// 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 680d8d2..85f42cf 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` for hints!
 
-// 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 b8c9b82..0c877aa 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` for hints!
 
-// 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/quiz2.rs b/exercises/quiz2.rs
index de0dce9..37c33a5 100644
--- a/exercises/quiz2.rs
+++ b/exercises/quiz2.rs
@@ -7,8 +7,6 @@
 // you think each value is. That is, add either `string_slice` or `string`
 // before the parentheses on each line. If you're right, it will compile!
 
-// I AM NOT DONE
-
 fn string_slice(arg: &str) {
     println!("{}", arg);
 }
@@ -17,14 +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("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/strings/strings1.rs b/exercises/strings/strings1.rs
index 8090244..75f3b33 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` for hints ;)
 
-// I AM NOT DONE
-
 fn main() {
     let answer = current_favorite_color();
     println!("My current favorite color is {}", answer);
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    "blue".into()
 }
diff --git a/exercises/strings/strings2.rs b/exercises/strings/strings2.rs
index 5a2ce74..a048f88 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` for hints :)
 
-// 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/structs/structs1.rs b/exercises/structs/structs1.rs
index 6d0b2f4..a1563a9 100644
--- a/exercises/structs/structs1.rs
+++ b/exercises/structs/structs1.rs
@@ -1,13 +1,12 @@
 // structs1.rs
 // Address all the TODOs to make the tests pass!
 
-// I AM NOT DONE
-
-struct ColorClassicStruct {
-    // TODO: Something goes here
+struct ColorClassicStruct<'a> {
+    name: &'a str,
+    hex: &'a str 
 }
 
-struct ColorTupleStruct(/* TODO: Something goes here */);
+struct ColorTupleStruct<'a>(&'a str, &'a str);
 
 #[derive(Debug)]
 struct UnitStruct;
@@ -19,7 +18,7 @@ mod tests {
     #[test]
     fn classic_c_structs() {
         // TODO: Instantiate a classic c struct!
-        // let green =
+        let green = ColorClassicStruct { name: "green", hex: "#00FF00" };
 
         assert_eq!(green.name, "green");
         assert_eq!(green.hex, "#00FF00");
@@ -28,7 +27,7 @@ mod tests {
     #[test]
     fn tuple_structs() {
         // TODO: Instantiate a tuple struct!
-        // let green =
+        let green = ColorTupleStruct("green", "#00FF00");
 
         assert_eq!(green.0, "green");
         assert_eq!(green.1, "#00FF00");
@@ -37,7 +36,7 @@ mod tests {
     #[test]
     fn unit_structs() {
         // TODO: Instantiate a unit struct!
-        // let unit_struct =
+        let unit_struct = UnitStruct;
         let message = format!("{:?}s are fun!", unit_struct);
 
         assert_eq!(message, "UnitStructs are fun!");
diff --git a/exercises/structs/structs2.rs b/exercises/structs/structs2.rs
index f9c6427..e3f4f0d 100644
--- a/exercises/structs/structs2.rs
+++ b/exercises/structs/structs2.rs
@@ -1,8 +1,6 @@
 // structs2.rs
 // Address all the TODOs to make the tests pass!
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 struct Order {
     name: String,
@@ -34,7 +32,12 @@ 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: "Hacker in Rust".into(),
+         count: order_template.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 06fcaf2..98c60dd 100644
--- a/exercises/structs/structs3.rs
+++ b/exercises/structs/structs3.rs
@@ -3,8 +3,6 @@
 // exercise we have defined the Package struct and we want to test some logic attached to it,
 // make the code compile and the tests pass! If you have issues execute `rustlings hint structs3`
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 struct Package {
     sender_country: String,
@@ -15,7 +13,7 @@ struct Package {
 impl Package {
     fn new(sender_country: String, recipient_country: String, weight_in_grams: i32) -> Package {
         if weight_in_grams <= 0 {
-            // Something goes here...
+            panic!("package must have a weight") 
         } else {
             return Package {
                 sender_country,
@@ -25,12 +23,12 @@ 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 
     }
 }
 
@@ -62,7 +60,7 @@ mod tests {
         let sender_country = String::from("Spain");
         let recipient_country = String::from("Spain");
 
-        let cents_per_gram = ???;
+        let cents_per_gram = 3;
 
         let package = Package::new(sender_country, recipient_country, 1500);