diff --git a/exercises/conversions/as_ref_mut.rs b/exercises/conversions/as_ref_mut.rs
index c9eed7d0..771a9bbf 100644
--- a/exercises/conversions/as_ref_mut.rs
+++ b/exercises/conversions/as_ref_mut.rs
@@ -3,24 +3,25 @@
 // and https://doc.rust-lang.org/std/convert/trait.AsMut.html, respectively.
 // Execute `rustlings hint as_ref_mut` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 // Obtain the number of bytes (not characters) in the given argument
 // Add the AsRef trait appropriately as a trait bound
-fn byte_counter<T>(arg: T) -> usize {
+fn byte_counter<T>(arg: T) -> usize
+where
+    T: AsRef<str>,
+{
     arg.as_ref().as_bytes().len()
 }
 
 // Obtain the number of characters (not bytes) in the given argument
 // Add the AsRef trait appropriately as a trait bound
-fn char_counter<T>(arg: T) -> usize {
+fn char_counter<T: AsRef<str>>(arg: T) -> usize {
     arg.as_ref().chars().count()
 }
 
 // Squares a number using as_mut(). Add the trait bound as is appropriate and
 // implement the function body.
-fn num_sq<T>(arg: &mut T) {
-    ???
+fn num_sq<T: AsMut<u32>>(arg: &mut T) {
+    *arg.as_mut() = arg.as_mut().pow(2);
 }
 
 #[cfg(test)]
diff --git a/exercises/conversions/try_from_into.rs b/exercises/conversions/try_from_into.rs
index 21f56fbc..4485b90d 100644
--- a/exercises/conversions/try_from_into.rs
+++ b/exercises/conversions/try_from_into.rs
@@ -62,14 +62,6 @@ impl TryFrom<[i16; 3]> for Color {
     type Error = IntoColorError;
     fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {
         let mut a: [u8; 3] = [0, 0, 0];
-        // arr.into_iter().enumerate().map(|(i, x)| {
-        //     let t: u8 = match x.try_into() {
-        //         Ok(i) => i,
-        //         Err(err) => {
-        //             return Err(IntoColorError::IntConversion);
-        //         }
-        //     };
-        // });
         for (i, x) in arr.into_iter().enumerate() {
             let tmp: u8 = match x.to_owned().try_into() {
                 Ok(i) => i,