diff --git a/Sprint-1/1-key-exercises/1-count.js b/Sprint-1/1-key-exercises/1-count.js
index 117bcb2b6e..5ec5fcc6d4 100644
--- a/Sprint-1/1-key-exercises/1-count.js
+++ b/Sprint-1/1-key-exercises/1-count.js
@@ -4,3 +4,8 @@ count = count + 1;
 
 // Line 1 is a variable declaration, creating the count variable with an initial value of 0
 // Describe what line 3 is doing, in particular focus on what = is doing
+
+// Answer: Line 3 is reassigning the value of the variable 'count' by adding 1 to its current value.
+// The = operator is used to update / assign a new value to the variable 'count'.
+// It takes the current value of 'count', adds 1 to it, and then assigns that new value back to 'count'.
+// 
diff --git a/Sprint-1/1-key-exercises/2-initials.js b/Sprint-1/1-key-exercises/2-initials.js
index 47561f6175..f0a1dc0e11 100644
--- a/Sprint-1/1-key-exercises/2-initials.js
+++ b/Sprint-1/1-key-exercises/2-initials.js
@@ -5,7 +5,8 @@ let lastName = "Johnson";
 // Declare a variable called initials that stores the first character of each string.
 // This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution.
 
-let initials = ``;
+let initials = `${firstName[0]}${middleName[0]}${lastName[0]}`;
+// console.log(initials);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 
diff --git a/Sprint-1/1-key-exercises/3-paths.js b/Sprint-1/1-key-exercises/3-paths.js
index ab90ebb28e..b96e4cd6a5 100644
--- a/Sprint-1/1-key-exercises/3-paths.js
+++ b/Sprint-1/1-key-exercises/3-paths.js
@@ -17,7 +17,7 @@ console.log(`The base part of ${filePath} is ${base}`);
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable
 
-const dir = ;
-const ext = ;
+const dir = filePath.slice(0, lastSlashIndex);
+const ext = base.slice(base.lastIndexOf(".") + 1);
 
 // https://www.google.com/search?q=slice+mdn
\ No newline at end of file
diff --git a/Sprint-1/1-key-exercises/4-random.js b/Sprint-1/1-key-exercises/4-random.js
index 292f83aabb..5bcabc4ee2 100644
--- a/Sprint-1/1-key-exercises/4-random.js
+++ b/Sprint-1/1-key-exercises/4-random.js
@@ -7,3 +7,9 @@ const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 // Try breaking down the expression and using documentation to explain what it means
 // It will help to think about the order in which expressions are evaluated
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+
+// Answer: The variable we have created 'num' generates a random number, this is done by using the Math.random() function
+// The Math.Random is a built-in function that creates a random number between 0 and 1, but not including 1. The next part
+// of the expression multiplies the random number by (100 - 1 + 1) which is 100, this means that the random number will be between 0 and 100.
+// Then +1 minimum is added to the random number, this means that the random number will be between 1 and 100. Finally, the Math.floor() 
+// function is used to round the random number down to the nearest whole number.
diff --git a/Sprint-1/2-mandatory-errors/0.js b/Sprint-1/2-mandatory-errors/0.js
index cf6c5039f7..65ad3030d6 100644
--- a/Sprint-1/2-mandatory-errors/0.js
+++ b/Sprint-1/2-mandatory-errors/0.js
@@ -1,2 +1,2 @@
-This is just an instruction for the first activity - but it is just for human consumption
-We don't want the computer to run these 2 lines - how can we solve this problem?
\ No newline at end of file
+//This is just an instruction for the first activity - but it is just for human consumption
+//We don't want the computer to run these 2 lines - how can we solve this problem?
\ No newline at end of file
diff --git a/Sprint-1/2-mandatory-errors/1.js b/Sprint-1/2-mandatory-errors/1.js
index 7a43cbea76..031839b47d 100644
--- a/Sprint-1/2-mandatory-errors/1.js
+++ b/Sprint-1/2-mandatory-errors/1.js
@@ -1,4 +1,4 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
diff --git a/Sprint-1/2-mandatory-errors/2.js b/Sprint-1/2-mandatory-errors/2.js
index e09b89831d..a05375657b 100644
--- a/Sprint-1/2-mandatory-errors/2.js
+++ b/Sprint-1/2-mandatory-errors/2.js
@@ -1,5 +1,4 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
 // what's the error ?
-
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);
\ No newline at end of file
diff --git a/Sprint-1/2-mandatory-errors/3.js b/Sprint-1/2-mandatory-errors/3.js
index ec101884db..73445fe93f 100644
--- a/Sprint-1/2-mandatory-errors/3.js
+++ b/Sprint-1/2-mandatory-errors/3.js
@@ -1,5 +1,11 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.toString().slice(-4);
+
+console.log(last4Digits);
+
+//The const Last4Digits should store the last 4 characters of the cardNumber and return it
+
+//The Built in method slice() doesnt work on numbers, only on strings.
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
diff --git a/Sprint-1/2-mandatory-errors/4.js b/Sprint-1/2-mandatory-errors/4.js
index 5f86c730bc..0b9796042a 100644
--- a/Sprint-1/2-mandatory-errors/4.js
+++ b/Sprint-1/2-mandatory-errors/4.js
@@ -1,2 +1,2 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const twelveHourClockTime = "8:53 pm";
+const twentyFourHourClockTime = "20:53";
diff --git a/Sprint-1/3-mandatory-interpret/1-percentage-change.js b/Sprint-1/3-mandatory-interpret/1-percentage-change.js
index e24ecb8e18..cd114a797d 100644
--- a/Sprint-1/3-mandatory-interpret/1-percentage-change.js
+++ b/Sprint-1/3-mandatory-interpret/1-percentage-change.js
@@ -2,7 +2,7 @@ let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
 carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
@@ -12,11 +12,16 @@ console.log(`The percentage change is ${percentageChange}`);
 // Read the code and then answer the questions below
 
 // a) How many function calls are there in this file? Write down all the lines where a function call is made
+// A) 5 in total - lines 4, 5, 10
 
 // b) Run the code and identify the line where the error is coming from - why is this error occurring? How can you fix this problem?
+// A) Missing comma in line 5 in function .replaceAll which is causing the error.
 
 // c) Identify all the lines that are variable reassignment statements
+// A) lines 4 and 5 are variable reassignment statements.
 
 // d) Identify all the lines that are variable declarations
+// A) Lines 1, 2, 7 and 8
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// A) The expression is converting the string value of carPrice into a number and removing the commas so that it can be used in a mathematical calculation.
\ No newline at end of file
diff --git a/Sprint-1/3-mandatory-interpret/2-time-format.js b/Sprint-1/3-mandatory-interpret/2-time-format.js
index 47d2395587..daee9398ab 100644
--- a/Sprint-1/3-mandatory-interpret/2-time-format.js
+++ b/Sprint-1/3-mandatory-interpret/2-time-format.js
@@ -12,14 +12,20 @@ console.log(result);
 // For the piece of code above, read the code and then answer the following questions
 
 // a) How many variable declarations are there in this program?
+// A) 6
 
 // b) How many function calls are there?
+// A) 1 (console.log function)
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// A) This expression is using the modulo operator that finds the remainder of the movieLength after being divided by 60.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// A) The expression is calculating the total number of minutes in the movie (not including the remaining seconds).
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// A) The variable gives the total length of the movie in hours, minutes, and seconds. A better name for this variable could be "formattedMovieLength".
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// A) The code would have an error if the user was to inputs a value with commas, letters or as a string.
\ No newline at end of file
diff --git a/Sprint-1/3-mandatory-interpret/3-to-pounds.js b/Sprint-1/3-mandatory-interpret/3-to-pounds.js
index 60c9ace69a..5f2268579d 100644
--- a/Sprint-1/3-mandatory-interpret/3-to-pounds.js
+++ b/Sprint-1/3-mandatory-interpret/3-to-pounds.js
@@ -25,3 +25,11 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 2. Line 3: uses the substring method to remove the "p" from the end of the string
+// 3. Line 8: the variable paddedPenceNumberString is used to ensure that the string has at least 3 characters,
+// if not it will add a zero to the start of the string
+// 4. Line 9 - 11: the variable pounds uses the substring method in the same way as line 3 but this time removes the last two characters
+// the result is now stored in the const 'pounds' to be used in the final output
+// 5. Line 14 - 16: the variable pence also uses the substring method to extract the last two characters from paddedPenceNumberString
+// the result is now stored in the const 'pence' to be used in the final output, a '0' is added to the end of the string if there is only one character
+// 6. Line 18: the console.log function prints our output - the values stored in the consts 'pounds' and 'pence'.
\ No newline at end of file
diff --git a/Sprint-2/1-key-errors/0.js b/Sprint-2/1-key-errors/0.js
index 653d6f5a07..a2d0051d0b 100644
--- a/Sprint-2/1-key-errors/0.js
+++ b/Sprint-2/1-key-errors/0.js
@@ -1,13 +1,12 @@
 // Predict and explain first...
-//  =============> write your prediction here
 
-// call the function capitalise with a string input
+//  =============> write your prediction here
+//(A) You are likely to encounter a syntax error because the variable `str` is being declared twice within the same scope
 // 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;
+  let capitalisedStr = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return capitalisedStr;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+console.log(capitalise("hello"));
diff --git a/Sprint-2/1-key-errors/1.js b/Sprint-2/1-key-errors/1.js
index f2d56151f4..839a64fa66 100644
--- a/Sprint-2/1-key-errors/1.js
+++ b/Sprint-2/1-key-errors/1.js
@@ -2,19 +2,14 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+// (A)An error will occur because the variable `decimalNumber` is being declared twice within the same scope
+
 
 // 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);
-
-// =============> write your explanation here
-
-// Finally, correct the code to fix the problem
-// =============> write your new code here
+console.log(convertToPercentage(0.5));
diff --git a/Sprint-2/1-key-errors/2.js b/Sprint-2/1-key-errors/2.js
index aad57f7cfe..a216c931ea 100644
--- a/Sprint-2/1-key-errors/2.js
+++ b/Sprint-2/1-key-errors/2.js
@@ -4,17 +4,18 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
-
-function square(3) {
-    return num * num;
-}
+// an error will occur because the value `3` has been put in the parentheses of the function.
 
 // =============> write the error message here
+// (A) SyntaxError: Unexpected number
 
 // =============> explain this error message here
+// (A)An error occurs because the function parameter `3` is a literal value instead of a variable name.
 
-// Finally, correct the code to fix the problem
 
-// =============> write your new code here
+function square(num) {
+    return num * num;
+}
+console.log(square(3));
 
 
diff --git a/Sprint-2/2-mandatory-debug/0.js b/Sprint-2/2-mandatory-debug/0.js
index b27511b417..8074baa422 100644
--- a/Sprint-2/2-mandatory-debug/0.js
+++ b/Sprint-2/2-mandatory-debug/0.js
@@ -1,14 +1,20 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+//(A) An error will occur because the function `multiply` does not return a value.
 
-function multiply(a, b) {
+/*function multiply(a, b) {
   console.log(a * b);
 }
 
-console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
+console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);*/
 
 // =============> write your explanation here
+// (A) It returns `undefined`. This results in the output being "The result of multiplying 10 and 32 is undefined".
+// 
+
+function multiply(a, b) {
+  return a * b;
+}
 
-// Finally, correct the code to fix the problem
-//  =============> write your new code here
+console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
diff --git a/Sprint-2/2-mandatory-debug/1.js b/Sprint-2/2-mandatory-debug/1.js
index 37cedfbcfd..7faaecbf40 100644
--- a/Sprint-2/2-mandatory-debug/1.js
+++ b/Sprint-2/2-mandatory-debug/1.js
@@ -1,13 +1,21 @@
 // Predict and explain first...
 //  =============> write your prediction here
+//(A) An error will occur because the function `sum` does not return a value. The `return` statement is followed by a semicolon, the function will return `undefined`
 
-function sum(a, b) {
+
+/*function sum(a, b) {
   return;
   a + b;
 }
 
-console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);*/
 
 // =============> write your explanation here
 // 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)}`);
\ No newline at end of file
diff --git a/Sprint-2/2-mandatory-debug/2.js b/Sprint-2/2-mandatory-debug/2.js
index 57d3f5dc35..e029d76e1d 100644
--- a/Sprint-2/2-mandatory-debug/2.js
+++ b/Sprint-2/2-mandatory-debug/2.js
@@ -2,8 +2,10 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// (A) The output will be "The last digit of... is 3" for all these due the the variable `num` being set to 103 and the function `getLastDigit`
 
-const num = 103;
+
+/*const num = 103;
 
 function getLastDigit() {
   return num.toString().slice(-1);
@@ -11,14 +13,31 @@ function getLastDigit() {
 
 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)}`);
+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
+//(A) As predicted the output resunts last digit of the variable `num`, which is set to 103. Therefore, regardless of the input values (42, 105, 806), the function always returns '3'.
+
 // 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
+//(A) The function `getLastDigit` needed to accept a parameter `num` in order to work properly.
diff --git a/Sprint-2/3-mandatory-implement/1-bmi.js b/Sprint-2/3-mandatory-implement/1-bmi.js
index 17b1cbde1b..b90426a33e 100644
--- a/Sprint-2/3-mandatory-implement/1-bmi.js
+++ b/Sprint-2/3-mandatory-implement/1-bmi.js
@@ -15,5 +15,9 @@
 // It should return their Body Mass Index to 1 decimal place
 
 function calculateBMI(weight, height) {
-    // return the BMI of someone based off their weight and height
-}
\ No newline at end of file
+    const heightSquared = height * height;
+    const bmi = weight / heightSquared;
+    return Number(bmi.toFixed(1));
+}
+
+//console.log(calculateBMI(80, 1.85)); // expected output: 23.4
\ No newline at end of file