diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..783cd8f80 100644
--- a/exercises/B-hello-world/exercise.js
+++ b/exercises/B-hello-world/exercise.js
@@ -1 +1,3 @@
 console.log("Hello world");
+console.log("Hello there javaScript");
+console.log();
diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..bb60c9438 100644
--- a/exercises/C-variables/exercise.js
+++ b/exercises/C-variables/exercise.js
@@ -1,3 +1,6 @@
-// Start by creating a variable `greeting`
+// Start by creating a letiable `greeting`
+let greeting = "helloWorld";
 
-console.log(greeting);
+for (let i = 0; i < 3; i++) {
+  console.log(greeting);
+}
diff --git a/exercises/D-strings/exercise.js b/exercises/D-strings/exercise.js
index 2cffa6a81..1522692a2 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,6 @@
-// Start by creating a variable `message`
+// Start by creating a letiable `message`
+let message = "Coding is best";
+let typeOfmessage = typeof message;
 
 console.log(message);
+console.log(typeOfmessage);
diff --git a/exercises/E-strings-concatenation/exercise.js b/exercises/E-strings-concatenation/exercise.js
index 2cffa6a81..c7cd5c11a 100644
--- a/exercises/E-strings-concatenation/exercise.js
+++ b/exercises/E-strings-concatenation/exercise.js
@@ -1,3 +1,6 @@
-// Start by creating a variable `message`
+// Start by creating a letiable `message`
+let greet = "hello";
+let name = "Andile";
+let message = `${greet} my name is  ${name}`;
 
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..6a54dda01 100644
--- a/exercises/F-strings-methods/exercise.js
+++ b/exercises/F-strings-methods/exercise.js
@@ -1,3 +1,6 @@
-// Start by creating a variable `message`
+// Start by creating a letiable `message`
+
+let name = "Andile";
+let message = `my name is ${name} and its ${name.length} characters long`;
 
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..a29195e61 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,5 @@
 const name = " Daniel  ";
+let name2 = name.trim();
+let message = `My name is ${name2} and its ${name2.length} characters long`;
 
 console.log(message);
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..74976b7fd 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,7 @@
-// Start by creating a variables `numberOfStudents` and `numberOfMentors`
+// Start by creating a letiables `numberOfStudents` and `numberOfMentors`
+let numberOfMentors = 8;
+let numberOfStudents = 15;
+let total = numberOfMentors + numberOfStudents;
+console.log(`Total number of students:${numberOfStudents}`);
+console.log(`Total number of mentors ${numberOfMentors}`);
+console.log(`The number of students and mentors is: ${total}`);
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..6e0f0ba1b 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,8 @@
-var numberOfStudents = 15;
-var numberOfMentors = 8;
+let numberOfStudents = 15;
+let numberOfMentors = 8;
+let studentPec =
+  (numberOfStudents / (numberOfMentors + numberOfStudents)) * 100;
+
+let mentorPec = (numberOfMentors / (numberOfMentors + numberOfStudents)) * 100;
+console.log("Percentage of students: " + Math.round(studentPec)) + "%";
+console.log("Percentage of mentors: " + Math.round(mentorPec)) + "%";
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..662b42af7 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,7 +1,10 @@
 function halve(number) {
-  // complete the function here
+  let answer = number / 2;
+  return answer;
 }
 
-var result = halve(12);
+let result = halve(12);
 
 console.log(result);
+console.log(halve(10));
+console.log(halve(14));
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..76b8866ed 100644
--- a/exercises/J-functions/exercise2.js
+++ b/exercises/J-functions/exercise2.js
@@ -1,7 +1,10 @@
 function triple(number) {
-  // complete function here
+  var answer = number * 3;
+  return answer;
 }
 
 var result = triple(12);
 
 console.log(result);
+console.log(triple(5));
+console.log(triple(3));
diff --git a/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..cb0b0d927 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,5 +1,6 @@
 // Complete the function so that it takes input parameters
-function multiply() {
+function multiply(num1, num2) {
+  return num1 * num2;
   // Calculate the result of the function and return it
 }
 
diff --git a/exercises/K-functions-parameters/exercise2.js b/exercises/K-functions-parameters/exercise2.js
index db7a8904b..8f0f0680b 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,5 +1,7 @@
 // Declare your function first
-
+function divide(num1, num2) {
+  return num1 / num2;
+}
 var result = divide(3, 4);
 
 console.log(result);
diff --git a/exercises/K-functions-parameters/exercise3.js b/exercises/K-functions-parameters/exercise3.js
index 537e9f4ec..c2ac2bc1c 100644
--- a/exercises/K-functions-parameters/exercise3.js
+++ b/exercises/K-functions-parameters/exercise3.js
@@ -1,4 +1,7 @@
 // Write your function here
+function createGreeting(name) {
+  return `Hello ${name}`;
+}
 
 var greeting = createGreeting("Daniel");
 
diff --git a/exercises/K-functions-parameters/exercise4.js b/exercises/K-functions-parameters/exercise4.js
index 7ab44589e..7abf6d1b8 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,8 @@
 // Declare your function first
+function add(num1, num2) {
+  return num1 + num2;
+}
 
 // Call the function and assign to a variable `sum`
-
+var sum = add(13, 124);
 console.log(sum);
diff --git a/exercises/K-functions-parameters/exercise5.js b/exercises/K-functions-parameters/exercise5.js
index 7c5bcd605..00508aeeb 100644
--- a/exercises/K-functions-parameters/exercise5.js
+++ b/exercises/K-functions-parameters/exercise5.js
@@ -1,4 +1,7 @@
 // Declare your function here
+function createLongGreeting(name, age) {
+  return `Hello my name is ${name} and i am ${age} years old.`;
+}
 
 const greeting = createLongGreeting("Daniel", 30);
 
diff --git a/exercises/L-functions-nested/excercise2.js b/exercises/L-functions-nested/excercise2.js
new file mode 100644
index 000000000..99d023bad
--- /dev/null
+++ b/exercises/L-functions-nested/excercise2.js
@@ -0,0 +1,17 @@
+var mentor1 = "Daniel";
+var mentor2 = "Irina";
+var mentor3 = "Mimi";
+var mentor4 = "Rob";
+var mentor5 = "Yohannes";
+
+function capitalLetter(name) {
+  return (name = name.toUpperCase());
+}
+function greeting(name) {
+  return "hello " + capitalLetter(name);
+}
+console.log(greeting(mentor1));
+console.log(greeting(mentor2));
+console.log(greeting(mentor3));
+console.log(greeting(mentor4));
+console.log(greeting(mentor5));
diff --git a/exercises/L-functions-nested/exercise.js b/exercises/L-functions-nested/exercise.js
index a5d377442..7bf909d9e 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -1,5 +1,11 @@
-var mentor1 = "Daniel";
-var mentor2 = "Irina";
-var mentor3 = "Mimi";
-var mentor4 = "Rob";
-var mentor5 = "Yohannes";
+//This function calculates the percentages.
+//provide the name of group you wish to calculate its percentage on name parameter
+function percentage(name, numberOfGroup, total) {
+  let result = (numberOfGroup / total) * 100;
+  function message() {
+    return `Percentages of ${name}: ${result}`;
+  }
+  return message();
+}
+console.log(percentage("Student", 40, 400));
+console.log(percentage("Mentors", 360, 400));
diff --git a/extra/1-currency-conversion.js b/extra/1-currency-conversion.js
index 70a2fe863..ff18fdc62 100644
--- a/extra/1-currency-conversion.js
+++ b/extra/1-currency-conversion.js
@@ -5,7 +5,9 @@
   Write a function that converts a price to USD (exchange rate is 1.4 $ to £)
 */
 
-function convertToUSD() {}
+function convertToUSD(euro) {
+  return euro * 1.4;
+}
 
 /*
   CURRENCY FORMATTING
@@ -15,7 +17,10 @@ function convertToUSD() {}
   They have also decided that they should add a 1% fee to all foreign transactions, which means you only convert 99% of the £ to BRL.
 */
 
-function convertToBRL() {}
+function convertToBRL(euro) {
+  let fee = (5.7 / 100) * 99;
+  return euro * fee;
+}
 
 /* ======= TESTS - DO NOT MODIFY ===== 
 There are some Tests in this file that will help you work out if your code is working.
diff --git a/extra/2-piping.js b/extra/2-piping.js
index 067dd0f5b..6fc4b806c 100644
--- a/extra/2-piping.js
+++ b/extra/2-piping.js
@@ -6,36 +6,37 @@
   - one that multiplies 2 numbers together
   - one that formats a number so it's returned as a string with a £ sign before it (e.g. 20 -> £20)
 
-  2. Using the variable startingValue as input, perform the following operations using your functions all
-  on one line (assign the result to the variable badCode):
+  2. Using the letiable startingValue as input, perform the following operations using your functions all
+  on one line (assign the result to the letiable badCode):
   - add 10 to startingValue
   - multiply the result by 2
   - format it
   
   3. Write a more readable version of what you wrote in step 2 under the BETTER PRACTICE comment. Assign
-  the final result to the variable goodCode
+  the final result to the letiable goodCode
 */
 
-function add() {
-
+function add(num1, num2) {
+  return num1 + num2;
 }
 
-function multiply() {
-
+function multiply(num1, num2) {
+  return num1 * num2;
 }
 
-function format() {
-
+function format(num) {
+  return "£" + num;
 }
 
-const startingValue = 2
+const startingValue = 2;
 
 // Why can this code be seen as bad practice? Comment your answer.
-let badCode = 
 
-/* BETTER PRACTICE */
+let badCode = "£" + (startingValue + add(10, 1) * multiply(1, 2));
 
-let goodCode = 
+/* BETTER PRACTICE */
+let answer = (startingValue + add(5, 5)) * multiply(1, 2);
+let goodCode = "£" + answer;
 
 /* ======= TESTS - DO NOT MODIFY ===== 
 There are some Tests in this file that will help you work out if your code is working.
@@ -43,22 +44,24 @@ There are some Tests in this file that will help you work out if your code is wo
 To run these tests type `node 2-piping.js` into your terminal
 */
 
-const util = require('util');
+const util = require("util");
 
 function test(test_name, actual, expected) {
-    let status;
-    if (actual === expected) {
-        status = "PASSED";
-    } else {
-        status = `FAILED: expected: ${util.inspect(expected)} but your code returned: ${util.inspect(actual)}`;
-    }
-
-    console.log(`${test_name}: ${status}`);
+  let status;
+  if (actual === expected) {
+    status = "PASSED";
+  } else {
+    status = `FAILED: expected: ${util.inspect(
+      expected
+    )} but your code returned: ${util.inspect(actual)}`;
+  }
+
+  console.log(`${test_name}: ${status}`);
 }
 
-test('add function - case 1 works', add(1,3), 4)
-test('add function - case 2 works', add(2.4,5), 7.4)
-test('multiply function works', multiply(2,3), 6)
-test('format function works', format(16), "£16")
-test('badCode variable correctly assigned', badCode, "£24")
-test('goodCode variable correctly assigned', goodCode, "£24")
+test("add function - case 1 works", add(1, 3), 4);
+test("add function - case 2 works", add(2.4, 5), 7.4);
+test("multiply function works", multiply(2, 3), 6);
+test("format function works", format(16), "£16");
+test("badCode letiable correctly assigned", badCode, "£24");
+test("goodCode letiable correctly assigned", goodCode, "£24");
diff --git a/extra/3-magic-8-ball.js b/extra/3-magic-8-ball.js
index e32182cfe..aa011d87d 100644
--- a/extra/3-magic-8-ball.js
+++ b/extra/3-magic-8-ball.js
@@ -46,6 +46,39 @@
 // This should log "The ball has shaken!"
 // and return the answer.
 function shakeBall() {
+  console.log("The ball has shaken!");
+  let array1 = [
+    [
+      "It is certain.",
+      "It is decidedly so.",
+      "Without a doubt.",
+      "Yes - definitely.",
+      "You may rely on it.",
+    ],
+    [
+      "As I see it, yes.",
+      "Most likely.",
+      "Outlook good.",
+      "Yes.",
+      "Signs point to yes.",
+    ],
+
+    [
+      " Reply hazy, try again.",
+      "Ask again later.",
+      "Better not tell you now.",
+      "Cannot predict now.",
+      "Concentrate and ask again.",
+    ],
+    [
+      "Don't count on it.",
+      "My reply is no.",
+      " My sources say no.",
+      "Outlook not so good.",
+      "Very doubtful.",
+    ],
+  ];
+  return array1[Math.floor(Math.random() * 3)][Math.floor(Math.random() * 3)];
   //Write your code in here
 }
 
@@ -59,7 +92,16 @@ function shakeBall() {
   This function should expect to be called with any value which was returned by the shakeBall function.
 */
 function checkAnswer(answer) {
-  //Write your code in here
+  let positivity = ["very positive", "positive", "negative", "very negative"];
+  if (answer === "It is decidedly so.") {
+    return positivity[0];
+  } else if (answer === "My reply is no.") {
+    return positivity[3];
+  } else if (answer === "It is decidedly so.") {
+    return positivity[0];
+  } else if (answer === "My reply is no.") {
+  }
+  return positivity[Math.floor(Math.random() * 3)];
 }
 
 /* 
diff --git a/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index 0a21afd1b..b4a25d2f8 100644
--- a/mandatory/1-syntax-errors.js
+++ b/mandatory/1-syntax-errors.js
@@ -1,16 +1,17 @@
 // There are syntax errors in this code - can you fix it to pass the tests?
 
-function addNumbers(a b c) {
-    return a + b + c;
+function addNumbers(a, b, c) {
+  return a + b + c;
 }
 
-function introduceMe(name, age)
-return "Hello, my name is " + name "and I am " age + "years old";
+function introduceMe(name, age) {
+  return "Hello, my name is " + name + "and I am " + age + "years old";
+}
 
 function getTotal(a, b) {
-    total = a ++ b;
+  total = a + b;
 
-    return "The total is total"
+  return "The total is total";
 }
 
 /* 
@@ -24,19 +25,25 @@ To run these tests type `node 1-syntax-errors.js` into your terminal
 ===================================================
 */
 
-const util = require('util');
+const util = require("util");
 
 function test(test_name, actual, expected) {
-    let status;
-    if (actual === expected) {
-        status = "PASSED";
-    } else {
-        status = `FAILED: expected: ${util.inspect(expected)} but your function returned: ${util.inspect(actual)}`;
-    }
-
-    console.log(`${test_name}: ${status}`);
+  let status;
+  if (actual === expected) {
+    status = "PASSED";
+  } else {
+    status = `FAILED: expected: ${util.inspect(
+      expected
+    )} but your function returned: ${util.inspect(actual)}`;
+  }
+
+  console.log(`${test_name}: ${status}`);
 }
 
 test("fixed addNumbers function - case 1", addNumbers(3, 4, 6), 13);
-test("fixed introduceMe function", introduceMe("Sonjide", 27), "Hello, my name is Sonjide and I am 27 years old");
+test(
+  "fixed introduceMe function",
+  introduceMe("Sonjide", 27),
+  "Hello, my name is Sonjide and I am 27 years old"
+);
 test("fixed getTotal function", getTotal(23, 5), "The total is 28");
diff --git a/mandatory/2-logic-error.js b/mandatory/2-logic-error.js
index 3c578ad87..1f1245b39 100644
--- a/mandatory/2-logic-error.js
+++ b/mandatory/2-logic-error.js
@@ -1,16 +1,15 @@
 // The syntax for this function is valid but it has an error, find it and fix it.
 
 function trimWord(word) {
-  return wordtrim();
+  return word.trim();
 }
 
 function getWordLength(word) {
-  return "word".length();
+  return word.length;
 }
 
 function multiply(a, b, c) {
-  a * b * c;
-  return;
+  return a * b * c;
 }
 
 /* 
diff --git a/mandatory/3-function-output.js b/mandatory/3-function-output.js
index c9221a200..90b9d3f40 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -1,9 +1,11 @@
 // Add comments to explain what this function does. You're meant to use Google!
+// The function picks a random number everytime the code runs and multiplies it  by ten
 function getNumber() {
   return Math.random() * 10;
 }
 
 // Add comments to explain what this function does. You're meant to use Google!
+// The function concatenates w1 and w2
 function s(w1, w2) {
   return w1.concat(w2);
 }
@@ -11,6 +13,7 @@ function s(w1, w2) {
 function concatenate(firstWord, secondWord, thirdWord) {
   // Write the body of this function to concatenate three words together.
   // Look at the test case below to understand what this function is expected to return.
+  return `${firstWord} ${secondWord} ${thirdWord}`;
 }
 
 /* 
diff --git a/mandatory/4-tax.js b/mandatory/4-tax.js
index c9e41c691..eb30c07a1 100644
--- a/mandatory/4-tax.js
+++ b/mandatory/4-tax.js
@@ -5,7 +5,10 @@
   Sales tax is 20% of the price of the product
 */
 
-function calculateSalesTax() {}
+function calculateSalesTax(num) {
+  var tax = (num / 100) * 20;
+  return num + tax;
+}
 
 /*
   CURRENCY FORMATTING
@@ -17,7 +20,9 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function addTaxAndFormatCurrency() {}
+function addTaxAndFormatCurrency(num) {
+  return `£${calculateSalesTax(num).toFixed(2)}`;
+}
 
 /* 
 ===================================================