diff --git a/Sprint-3/1-key-errors/0.js b/Sprint-3/1-key-errors/0.js
index 653d6f5a0..34bce0941 100644
--- a/Sprint-3/1-key-errors/0.js
+++ b/Sprint-3/1-key-errors/0.js
@@ -1,13 +1,12 @@
 // Predict and explain first...
-//  =============> write your prediction here
+  // Prediction: I think the code will have a SyntaxError because 'str' is declared twice.
 
 // 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)}`;
-  return str;
+return `${str[0].toUpperCase()}${str.slice(1)}`;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+  // Explanation:  The function already has something called str. You can't make a second thing with the same name inside the same function
+  // New code: removed the 'let str =' line and returned the expression directly.
diff --git a/Sprint-3/1-key-errors/1.js b/Sprint-3/1-key-errors/1.js
index f2d56151f..d8526afa4 100644
--- a/Sprint-3/1-key-errors/1.js
+++ b/Sprint-3/1-key-errors/1.js
@@ -1,20 +1,22 @@
 // Predict and explain first...
 
-// Why will an error occur when this program runs?
-// =============> write your prediction here
-
+// Why will an error occur when this program runs
+    // When this program runs there will be an identifier SyntaxError because 'decimalNumber' has already been declared
+    // Also the output will print a decimal since it says console.log(decimalNumber);
 // 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
+// 'decimalNumber' is already declared in two different areas in the same function which JavaScript does not allow.
+// 'decimalNumber' is only useful inside the function, so it will give an error of not knowing what decimalNumber is,
+//  even if it succeeds it will give the wrong output since what we are looking for is the percentage.
 
 // Finally, correct the code to fix the problem
-// =============> write your new code here
+//  New code: 1. Removed the duplicate `const decimalNumber = 0.5;` line.
+//            2. Changed the console.log to call the function and print the result.
diff --git a/Sprint-3/1-key-errors/2.js b/Sprint-3/1-key-errors/2.js
index aad57f7cf..055fe4632 100644
--- a/Sprint-3/1-key-errors/2.js
+++ b/Sprint-3/1-key-errors/2.js
@@ -3,18 +3,19 @@
 
 // this function should square any number but instead we're going to get an error
 
-// =============> write your prediction of the error here
+// Prediction: there is going to be an error because there is a number in the parameter
 
-function square(3) {
+function square(num) {
     return num * num;
 }
 
-// =============> write the error message here
+// it showed SyntaxError: Unexpected number
 
-// =============> explain this error message here
+// the parameter of a function must be a name /identifier, not a number.
+// JavaScript expected a word as a parameter but fond a number instead hence the SyntaxError.
 
 // Finally, correct the code to fix the problem
 
-// =============> write your new code here
+// New code : replaced  the parameter with a valid identifier
 
 
diff --git a/Sprint-3/2-mandatory-debug/0.js b/Sprint-3/2-mandatory-debug/0.js
index b27511b41..2509f2bfb 100644
--- a/Sprint-3/2-mandatory-debug/0.js
+++ b/Sprint-3/2-mandatory-debug/0.js
@@ -1,14 +1,15 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// Prediction:I think it will print 320, but the template string might not show the right result, but will return nothing.
 
 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
+// because console.log will print whatever it is given . 
+// the function has no return statement, so when we run the code it will say undefined because there is nothing to give back.
 
 // Finally, correct the code to fix the problem
 //  =============> write your new code here
diff --git a/Sprint-3/2-mandatory-debug/1.js b/Sprint-3/2-mandatory-debug/1.js
index 37cedfbcf..2090aada8 100644
--- a/Sprint-3/2-mandatory-debug/1.js
+++ b/Sprint-3/2-mandatory-debug/1.js
@@ -1,13 +1,13 @@
 // Predict and explain first...
-//  =============> write your prediction here
+// =====> It will not run and will come out as undefined
 
 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
-// Finally, correct the code to fix the problem
+// =====> There is a semicolon right after return, which tells it to stop there,
+// so basically anything that comes after that will not run hence the undefined result.
+// Finally, correct the code to fix the problem will be to remove the semicolon.
 //  =============> write your new code here
diff --git a/Sprint-3/2-mandatory-debug/2.js b/Sprint-3/2-mandatory-debug/2.js
index 57d3f5dc3..8c1d2766a 100644
--- a/Sprint-3/2-mandatory-debug/2.js
+++ b/Sprint-3/2-mandatory-debug/2.js
@@ -1,7 +1,7 @@
 // Predict and explain first...
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+// =============> I think the result prints will always be 3 as num will always be 103.
 
 const num = 103;
 
@@ -14,11 +14,23 @@ console.log(`The last digit of 105 is ${getLastDigit(105)}`);
 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
+// =============> because the code is using the outer variable num which is always 103.
+//                so every call is returning the last digit of 103.
 // Finally, correct the code to fix the problem
-// =============> write your new code here
+// =============> 
+function getLastDigit(num) {
+  return num.toString().slice(-1);
+}
+
+console.log(`The last digit of 42 is ${getLastDigit(42)}`);
+console.log(`The last digit of 105 is ${getLastDigit(105)}`);
+console.log(`The last digit of 806 is ${getLastDigit(806)}`);
+
 
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem
+// because there was no parameter so the function has no way of receiving the numbers. so adding a parameter fixes it.
\ 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..6fcfc1731 100644
--- a/Sprint-3/3-mandatory-implement/1-bmi.js
+++ b/Sprint-3/3-mandatory-implement/1-bmi.js
@@ -15,5 +15,7 @@
 // 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
+ return (weight / (height*height)). toFixed(1);
 }
+
+console.log(calculateBMI(70, 1.73));
diff --git a/Sprint-3/3-mandatory-implement/2-cases.js b/Sprint-3/3-mandatory-implement/2-cases.js
index 5b0ef77ad..75276cf8c 100644
--- a/Sprint-3/3-mandatory-implement/2-cases.js
+++ b/Sprint-3/3-mandatory-implement/2-cases.js
@@ -14,3 +14,9 @@
 // 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) {
+    return str.toUpperCase().replaceAll(" ", "_");
+}
+
+console.log(toUpperSnakeCase("hello there"));       // "HELLO_THERE"
+console.log(toUpperSnakeCase("lord of the rings")); // "LORD_OF_THE_RINGS"
\ No newline at end of file
diff --git a/Sprint-3/3-mandatory-implement/3-to-pounds.js b/Sprint-3/3-mandatory-implement/3-to-pounds.js
index 10754da73..c123214d2 100644
--- a/Sprint-3/3-mandatory-implement/3-to-pounds.js
+++ b/Sprint-3/3-mandatory-implement/3-to-pounds.js
@@ -4,3 +4,13 @@
 // 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(penceString) {
+  const pence = Number(penceString.replace("p", ""));
+  return `£${(pence / 100).toFixed(2)}`;
+}
+
+console.log(toPounds("399p"));
+console.log(toPounds("5p"));
+console.log(toPounds("50p"));
+console.log(toPounds("1250p"));
+console.log(toPounds("0p"));
\ No newline at end of file
diff --git a/Sprint-3/4-mandatory-interpret/time-format.js b/Sprint-3/4-mandatory-interpret/time-format.js
index c0dd9c9a5..6216bc5aa 100644
--- a/Sprint-3/4-mandatory-interpret/time-format.js
+++ b/Sprint-3/4-mandatory-interpret/time-format.js
@@ -21,18 +21,19 @@ function formatTimeDisplay(seconds) {
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
+// =============> 3 times because the return statement has three pad() calls in it. Hrs, Mins, Secs.
 
 // 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 first pad call pad(totalHours) worked out to 0
 
 // c) What is the return value of pad when it is called for the first time?
-// =============> write your answer here
+// =============> The value is 00, add another because every pad wants 2 digits. 
 
 // 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 last pad call receives 1 as its num because last call called is pad(remainingSeconds) which is calculated as seconds % 60.
+//                and with the seconds being 61, that's 61 % 60 giving 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
+// =============> The call is pad(1) and the pad adds a 0 to make the string 2 digits