diff --git a/Sprint-3/1-key-errors/0.js b/Sprint-3/1-key-errors/0.js
index 653d6f5a0..c6c7dffed 100644
--- a/Sprint-3/1-key-errors/0.js
+++ b/Sprint-3/1-key-errors/0.js
@@ -10,4 +10,17 @@ function capitalise(str) {
 }
 
 // =============> write your explanation here
+//The error occurs because the variable "str" is being 
+//declared twice in the same scope. The parameter "str" 
+//is already defined as a function argument, and then it 
+//is being redeclared with "let str =". This causes 
+//a syntax error because we cannot declare a variable 
+//with the same name in the same scope. To fix this, we 
+//can either rename the parameter or the variable inside 
+//the function.
+
 // =============> write your new code here
+function capitalise(str) {
+  let capitalisedStr = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return capitalisedStr;
+}
diff --git a/Sprint-3/1-key-errors/1.js b/Sprint-3/1-key-errors/1.js
index f2d56151f..a14d08fde 100644
--- a/Sprint-3/1-key-errors/1.js
+++ b/Sprint-3/1-key-errors/1.js
@@ -2,7 +2,13 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
-
+ //An error will occur because the variable "decimalNumber"
+ //is being declared twice in the same scope. 
+ //The parameter "decimalNumber" is already defined as a 
+ //function argument, and then it is being redeclared 
+ //with "const decimalNumber = 0.5;". This causes a 
+ //syntax error because we cannot declare a variable 
+ //with the same name in the same scope.
 // Try playing computer with the example to work out what is going on
 
 function convertToPercentage(decimalNumber) {
@@ -16,5 +22,20 @@ console.log(decimalNumber);
 
 // =============> write your explanation here
 
+//The error occurs because the variable "decimalNumber" is being 
+//declared twice in the same scope. The parameter "decimalNumber" 
+//is already defined as a function argument, and then it is being 
+//redeclared with "const decimalNumber = 0.5;". This causes a 
+//syntax error because we cannot declare a variable with the 
+//same name in the same scope. To fix this, we can either rename 
+//the parameter or the variable inside the function.
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+function convertToPercentage(decimalNumber) {
+  const percentage = `${decimalNumber * 100}%`;
+
+  return percentage;
+}
+
+console.log(convertToPercentage(0.5));
\ No newline at end of file
diff --git a/Sprint-3/1-key-errors/2.js b/Sprint-3/1-key-errors/2.js
index aad57f7cf..d815abfff 100644
--- a/Sprint-3/1-key-errors/2.js
+++ b/Sprint-3/1-key-errors/2.js
@@ -4,17 +4,24 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// I predict that there will be a syntax error because the parameter name "3" is not a valid
+//  identifier.
 
 function square(3) {
     return num * num;
 }
 
 // =============> write the error message here
+// SyntaxError: Function argument name must be a valid identifier
 
 // =============> explain this error message here
+// The error occurs because "3" is not a valid identifier for a function parameter. 
+// In JavaScript, parameter names must follow the rules for identifiers, which means they 
+// cannot be numbers or reserved keywords.
 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
-
-
+function square(num) {
+    return num * num;
+}
\ No newline at end of file
diff --git a/Sprint-3/2-mandatory-debug/0.js b/Sprint-3/2-mandatory-debug/0.js
index b27511b41..661d6e2ed 100644
--- a/Sprint-3/2-mandatory-debug/0.js
+++ b/Sprint-3/2-mandatory-debug/0.js
@@ -1,6 +1,9 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+// I predict that the output of the console.log statement will be "The result of multiplying
+//  10 and 32 is undefined" because the multiply function does not return a value, it only 
+// logs the result to the console.
 
 function multiply(a, b) {
   console.log(a * b);
@@ -9,6 +12,15 @@ function multiply(a, b) {
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
+// The multiply function takes two parameters, a and b, and logs the product of a and b to 
+// the console. However, it does not return any value. When the function is called inside 
+// the template literal, it returns undefined, which is why the output of the console.log 
+// statement includes "undefined".
 
 // Finally, correct the code to fix the problem
 //  =============> write your new code here
+function multiply(a, b) {
+  return a * b;
+}
+
+console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
diff --git a/Sprint-3/2-mandatory-debug/1.js b/Sprint-3/2-mandatory-debug/1.js
index 37cedfbcf..69247bf99 100644
--- a/Sprint-3/2-mandatory-debug/1.js
+++ b/Sprint-3/2-mandatory-debug/1.js
@@ -1,5 +1,8 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// I predict that the output of the console.log statement will be "The sum of 10 and 32 
+// is undefined" because the sum function does not return a value, it only has a return 
+// statement without any value.
 
 function sum(a, b) {
   return;
@@ -9,5 +12,16 @@ function sum(a, b) {
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+
+// The sum function takes two parameters, a and b, and has a return statement without
+// any value. This means that when the function is called, it will return undefined. 
+// Therefore, when the function is called inside the template literal, it returns 
+// undefined, which is why the output of the console.log statement includes "undefined".
+
 // Finally, correct the code to fix the problem
 //  =============> write your new code here
+function sum(a, b) {
+  return a + b;
+}
+
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
diff --git a/Sprint-3/2-mandatory-debug/2.js b/Sprint-3/2-mandatory-debug/2.js
index 57d3f5dc3..04974992d 100644
--- a/Sprint-3/2-mandatory-debug/2.js
+++ b/Sprint-3/2-mandatory-debug/2.js
@@ -3,6 +3,10 @@
 // Predict the output of the following code:
 // =============> Write your prediction here
 
+// I predict that the output of the console.log statements will be "The last digit of 42 is 3", 
+// "The last digit of 105 is 3", and "The last digit of 806 is 3" because the getLastDigit 
+// function always returns the last digit of the number 103, which is 3.
+
 const num = 103;
 
 function getLastDigit() {
@@ -15,10 +19,25 @@ 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
+// The last digit of 42 is 3
+// The last digit of 105 is 3
+// The last digit of 806 is 3
+
 // Explain why the output is the way it is
 // =============> write your explanation here
+// The getLastDigit function is not working properly because it always returns the last 
+// digit of the number 103, regardless of the input. This is because the function does not 
+// take any parameters and uses a global variable.
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
 
+function getLastDigit(num) {
+  return num.toString().slice(-1);
+}
+
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem
+// The getLastDigit function is not working properly because it does not take any parameters
+// and uses a global variable. To fix the problem, we need to add a parameter to the function 
+// so that it can take in a number and return the last digit of that number.
\ No newline at end of file
diff --git a/Sprint-3/3-mandatory-implement/1-bmi.js b/Sprint-3/3-mandatory-implement/1-bmi.js
index 58b1085f1..3258039dc 100644
--- a/Sprint-3/3-mandatory-implement/1-bmi.js
+++ b/Sprint-3/3-mandatory-implement/1-bmi.js
@@ -16,4 +16,8 @@
 
 function calculateBMI(weight, height) {
   // return the BMI of someone based off their weight and height
+  const bmi = weight / (height * height);
+  return bmi.toFixed(1); 
 }
+
+console.log(calculateBMI(70, 1.73)); // Output: "23.4"
diff --git a/Sprint-3/3-mandatory-implement/2-cases.js b/Sprint-3/3-mandatory-implement/2-cases.js
index 5b0ef77ad..39f88b1b2 100644
--- a/Sprint-3/3-mandatory-implement/2-cases.js
+++ b/Sprint-3/3-mandatory-implement/2-cases.js
@@ -14,3 +14,17 @@
 // 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(inputString) {
+  // Split the input string into words using space as the delimiter
+  const words = inputString.split(' ');
+
+  // Join the words with underscores and convert to uppercase
+  const upperSnakeCaseString = words.join('_').toUpperCase();
+
+  return upperSnakeCaseString;
+}
+
+
+console.log(toUpperSnakeCase("hello there")); // Output: "HELLO_THERE"
+console.log(toUpperSnakeCase("lord of the rings")); // Output: "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..ef221f713 100644
--- a/Sprint-3/3-mandatory-implement/3-to-pounds.js
+++ b/Sprint-3/3-mandatory-implement/3-to-pounds.js
@@ -1,6 +1,53 @@
 // In Sprint-1, there is a program written in 3-mandatory-interpret/3-to-pounds.js
 
 // You will need to take this code and turn it into a reusable block of code.
+
+const penceString = "399p";
+
+const penceStringWithoutTrailingP = penceString.substring(
+  0,
+  penceString.length - 1
+);
+
+const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+const pounds = paddedPenceNumberString.substring(
+  0,
+  paddedPenceNumberString.length - 2
+);
+
+const pence = paddedPenceNumberString
+  .substring(paddedPenceNumberString.length - 2)
+  .padEnd(2, "0");
+
+console.log(`£${pounds}.${pence}`);
+
+
 // You will need to declare a function called toPounds with an appropriately named parameter.
 
+function toPounds(penceString) {
+  const penceStringWithoutTrailingP = penceString.substring(
+    0,
+    penceString.length - 1
+  );
+
+  const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+  const pounds = paddedPenceNumberString.substring(
+    0,
+    paddedPenceNumberString.length - 2
+  );
+
+  const pence = paddedPenceNumberString
+    .substring(paddedPenceNumberString.length - 2)
+    .padEnd(2, "0");
+
+  return `£${pounds}.${pence}`;
+}
+
 // You should call this function a number of times to check it works for different inputs
+
+console.log(toPounds("399p")); // Output: £3.99
+console.log(toPounds("5p"));   // Output: £0.05
+console.log(toPounds("1234p")); // Output: £12.34
+console.log(toPounds("0p"));    // Output: £0.00
+
+
diff --git a/Sprint-3/4-mandatory-interpret/time-format.js b/Sprint-3/4-mandatory-interpret/time-format.js
index c0dd9c9a5..e41e7bbb8 100644
--- a/Sprint-3/4-mandatory-interpret/time-format.js
+++ b/Sprint-3/4-mandatory-interpret/time-format.js
@@ -23,16 +23,31 @@ function formatTimeDisplay(seconds) {
 // a) When formatTimeDisplay is called how many times will pad be called?
 // =============> write your answer here
 
+//formatTimeDisplay will call pad three times, once for totalHours, once for 
+// remainingMinutes, and once for remainingSeconds.
+
 // 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
+// The value assigned to num when pad is called for the first time is 0, which is the value 
+// of totalHours when the input is 61 seconds.
 
 // c) What is the return value of pad when it is called for the first time?
 // =============> write your answer here
 
+// The return value of pad when it is called for the first time is "00", which is the string
+//  representation of totalHours padded with a leading zero.
+
 // 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
+// The value assigned to num when pad is called for the last time in this program is 1, 
+// which is the value of remainingSeconds when the input is 61 seconds. This is because 61 
+// seconds has 1 second remaining after calculating the total minutes and hours.
 
 // 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
+// The return value of pad when it is called for the last time in this program is "01", 
+// which is the string representation of remainingSeconds padded with a leading zero. 
+// This is because the value of remainingSeconds is 1, and the pad function adds a leading 
+// zero to make it a two-digit string.