diff --git a/Sprint-3/1-key-errors/0.js b/Sprint-3/1-key-errors/0.js
index 653d6f5a0..8b1ff082d 100644
--- a/Sprint-3/1-key-errors/0.js
+++ b/Sprint-3/1-key-errors/0.js
@@ -1,13 +1,13 @@
 // Predict and explain first...
-//  =============> write your prediction here
+// ===========> I predict there will be an error when the function is called.
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
 
 function capitalise(str) {
-  let str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
-
-// =============> write your explanation here
-// =============> write your new code here
+capitalise("hello");
+// ===========> The error happens because str has already been declared as a function parameter.
+// ===========> Removed let because str is already declared as a function parameter.
diff --git a/Sprint-3/1-key-errors/1.js b/Sprint-3/1-key-errors/1.js
index f2d56151f..dcd511381 100644
--- a/Sprint-3/1-key-errors/1.js
+++ b/Sprint-3/1-key-errors/1.js
@@ -1,20 +1,19 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+// ===========> I predict there will be an error because decimalNumber is declared more than once.
 
 // Try playing computer with the example to work out what is going on
 
 function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
   const percentage = `${decimalNumber * 100}%`;
 
   return percentage;
 }
 
-console.log(decimalNumber);
+console.log(convertToPercentage(0.5));
 
-// =============> write your explanation here
+// ===========> The error happens because decimalNumber is already declared as a function parameter.
 
 // Finally, correct the code to fix the problem
-// =============> write your new code here
+// ===========> Removed the duplicate declaration and called the function with 0.5.
diff --git a/Sprint-3/1-key-errors/2.js b/Sprint-3/1-key-errors/2.js
index aad57f7cf..b3cd2a0e7 100644
--- a/Sprint-3/1-key-errors/2.js
+++ b/Sprint-3/1-key-errors/2.js
@@ -1,20 +1,17 @@
-
 // Predict and explain first BEFORE you run any code...
 
 // this function should square any number but instead we're going to get an error
 
-// =============> write your prediction of the error here
+// ===========> I predict there will be a syntax error because 3 cannot be used as a function parameter.
 
-function square(3) {
-    return num * num;
+function square(num) {
+  return num * num;
 }
 
-// =============> write the error message here
+// ===========> SyntaxError: Unexpected number
 
-// =============> explain this error message here
+// ===========> The error happens because a number cannot be used as a function parameter name.
 
 // Finally, correct the code to fix the problem
 
-// =============> write your new code here
-
-
+// ===========> Changed 3 to num so the function has a valid parameter name.
diff --git a/Sprint-3/2-mandatory-debug/0.js b/Sprint-3/2-mandatory-debug/0.js
index b27511b41..b7796990d 100644
--- a/Sprint-3/2-mandatory-debug/0.js
+++ b/Sprint-3/2-mandatory-debug/0.js
@@ -1,14 +1,14 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// ===========> I predict the multiplication will print 320, but the final result will show undefined.
 
 function multiply(a, b) {
-  console.log(a * b);
+  return a * b;
 }
 
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
-// =============> write your explanation here
+// ===========> The function prints the result instead of returning it, so the function returns undefined.
 
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+// ===========> Changed console.log to return so the function returns the multiplication result.
diff --git a/Sprint-3/2-mandatory-debug/1.js b/Sprint-3/2-mandatory-debug/1.js
index 37cedfbcf..6d6c87ab7 100644
--- a/Sprint-3/2-mandatory-debug/1.js
+++ b/Sprint-3/2-mandatory-debug/1.js
@@ -1,13 +1,12 @@
 // Predict and explain first...
-//  =============> write your prediction here
+// ===========> I predict the result will be undefined because the function returns before adding the numbers.
 
 function sum(a, b) {
-  return;
-  a + b;
+  return a + b;
 }
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
-// =============> write your explanation here
+// ===========> The function returns before a + b is calculated, so the result is undefined.
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+// ===========> Changed the return statement so it returns a + b.
diff --git a/Sprint-3/2-mandatory-debug/2.js b/Sprint-3/2-mandatory-debug/2.js
index 57d3f5dc3..9464d3e19 100644
--- a/Sprint-3/2-mandatory-debug/2.js
+++ b/Sprint-3/2-mandatory-debug/2.js
@@ -1,11 +1,9 @@
 // Predict and explain first...
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+// ===========> I predict all three results will be 3 because the function always uses num, which is 103.
 
-const num = 103;
-
-function getLastDigit() {
+function getLastDigit(num) {
   return num.toString().slice(-1);
 }
 
@@ -15,10 +13,11 @@ console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 
 // Now run the code and compare the output to your prediction
 // =============> write the output here
-// Explain why the output is the way it is
+// ============> The output is 3 for all three numbers.
+// ============> The function ignores the numbers passed to it and always uses num, which is 103.
 // =============> write your explanation here
 // Finally, correct the code to fix the problem
-// =============> write your new code here
+// ============> Added num as a parameter so the function uses the number passed to it.
 
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem
diff --git a/Sprint-3/3-mandatory-implement/1-bmi.js b/Sprint-3/3-mandatory-implement/1-bmi.js
index 58b1085f1..5f3087d30 100644
--- a/Sprint-3/3-mandatory-implement/1-bmi.js
+++ b/Sprint-3/3-mandatory-implement/1-bmi.js
@@ -15,5 +15,6 @@
 // It should return a string of their Body Mass Index to 1 decimal place
 
 function calculateBMI(weight, height) {
-  // return the BMI of someone based off their weight and height
+  const bmi = weight / (height * height);
+  return bmi.toFixed(1);
 }
diff --git a/Sprint-3/3-mandatory-implement/2-cases.js b/Sprint-3/3-mandatory-implement/2-cases.js
index 5b0ef77ad..d4ea8b64c 100644
--- a/Sprint-3/3-mandatory-implement/2-cases.js
+++ b/Sprint-3/3-mandatory-implement/2-cases.js
@@ -14,3 +14,10 @@
 // You will need to come up with an appropriate name for the function
 // Use the MDN string documentation to help you find a solution
 // This might help https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toUpperCase
+function toUpperSnakeCase(str) {
+  const upperCaseString = str.toUpperCase();
+  const snakeCaseString = upperCaseString.replaceAll(" ", "_");
+  return snakeCaseString;
+}
+console.log(toUpperSnakeCase("hello there"));
+console.log(toUpperSnakeCase("lord of the rings"));
diff --git a/Sprint-3/3-mandatory-implement/3-to-pounds.js b/Sprint-3/3-mandatory-implement/3-to-pounds.js
index 10754da73..74997ebc0 100644
--- a/Sprint-3/3-mandatory-implement/3-to-pounds.js
+++ b/Sprint-3/3-mandatory-implement/3-to-pounds.js
@@ -4,3 +4,12 @@
 // You will need to declare a function called toPounds with an appropriately named parameter.
 
 // You should call this function a number of times to check it works for different inputs
+function toPounds(pence) {
+  const penceNumber = Number(pence.replace("p", ""));
+  const pounds = penceNumber / 100;
+  return `£${pounds.toFixed(2)}`;
+}
+
+console.log(toPounds("399p"));
+console.log(toPounds("5p"));
+console.log(toPounds("2500p"));
diff --git a/Sprint-3/4-mandatory-interpret/time-format.js b/Sprint-3/4-mandatory-interpret/time-format.js
index c0dd9c9a5..032be965c 100644
--- a/Sprint-3/4-mandatory-interpret/time-format.js
+++ b/Sprint-3/4-mandatory-interpret/time-format.js
@@ -21,18 +21,18 @@ function formatTimeDisplay(seconds) {
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
+// ============> 3 times
 
 // Call formatTimeDisplay with an input of 61, now answer the following:
 
 // b) What is the value assigned to num when pad is called for the first time?
-// =============> write your answer here
+// ============> 0
 
 // c) What is the return value of pad when it is called for the first time?
-// =============> write your answer here
+// ============> "00"
 
-// d) What is the value assigned to num when pad is called for the last time in this program?  Explain your answer
-// =============> write your answer here
+// d) What is the value assigned to num when pad is called for the last time in this program? Explain your answer
+// ============> 1, because remainingSeconds is 1.
 
-// e) What is the return value of pad when it is called for the last time in this program?  Explain your answer
-// =============> write your answer here
+// e) What is the return value of pad when it is called for the last time in this program? Explain your answer
+// ============> "01", because pad adds a 0 to make the value two characters long.
diff --git a/Sprint-3/5-stretch-extend/format-time.js b/Sprint-3/5-stretch-extend/format-time.js
index 32a32e66b..2fc1732bd 100644
--- a/Sprint-3/5-stretch-extend/format-time.js
+++ b/Sprint-3/5-stretch-extend/format-time.js
@@ -4,22 +4,25 @@
 
 function formatAs12HourClock(time) {
   const hours = Number(time.slice(0, 2));
+  const minutes = time.slice(2);
+
+  if (hours === 0) {
+    return `12${minutes} am`;
+  }
+
+  if (hours === 12) {
+    return `12${minutes} pm`;
+  }
+
   if (hours > 12) {
-    return `${hours - 12}:00 pm`;
+    return `${String(hours - 12).padStart(2, "0")}${minutes} pm`;
   }
-  return `${time} am`;
-}
 
-const currentOutput = formatAs12HourClock("08:00");
-const targetOutput = "08:00 am";
-console.assert(
-  currentOutput === targetOutput,
-  `current output: ${currentOutput}, target output: ${targetOutput}`
-);
+  return `${String(hours).padStart(2, "0")}${minutes} am`;
+}
 
-const currentOutput2 = formatAs12HourClock("23:00");
-const targetOutput2 = "11:00 pm";
-console.assert(
-  currentOutput2 === targetOutput2,
-  `current output: ${currentOutput2}, target output: ${targetOutput2}`
-);
+console.assert(formatAs12HourClock("08:00") === "08:00 am");
+console.assert(formatAs12HourClock("23:00") === "11:00 pm");
+console.assert(formatAs12HourClock("00:00") === "12:00 am");
+console.assert(formatAs12HourClock("12:00") === "12:00 pm");
+console.assert(formatAs12HourClock("13:30") === "01:30 pm");