diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..c8dea5533 100644
--- a/exercises/B-hello-world/exercise.js
+++ b/exercises/B-hello-world/exercise.js
@@ -1 +1 @@
-console.log("Hello world");
+console.log("'Hello World. I just started learning JavaScript!'");
diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..720e13ae8 100644
--- a/exercises/C-variables/exercise.js
+++ b/exercises/C-variables/exercise.js
@@ -1,3 +1,8 @@
 // Start by creating a variable `greeting`
 
-console.log(greeting);
+var greeting = "Hello world";
+for (var x = 0; x < 3; x++) {
+  console.log(greeting);
+}
+
+//console.log(greeting);
diff --git a/exercises/D-strings/exercise.js b/exercises/D-strings/exercise.js
index 2cffa6a81..52967790f 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,7 @@
 // Start by creating a variable `message`
 
+var message = "this is a string";
+var messageType = typeof message;
+
 console.log(message);
+console.log(messageType);
diff --git a/exercises/E-strings-concatenation/exercise.js b/exercises/E-strings-concatenation/exercise.js
index 2cffa6a81..d121e1539 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`
+var greetingMassage = "hello ,";
+var myName = "my name is Mohammed !";
+var message = greetingMassage + myName;
 
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..40268f6d5 100644
--- a/exercises/F-strings-methods/exercise.js
+++ b/exercises/F-strings-methods/exercise.js
@@ -1,3 +1,12 @@
 // Start by creating a variable `message`
+const myName = "Mohammed";
+const myNameLength = myName.length;
+var message =
+  " my name is " +
+  myName +
+  " and my name length is " +
+  myNameLength +
+  " characters long";
+console.log(message);
 
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..f8723cce0 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,7 @@
 const name = " Daniel  ";
 
-console.log(message);
+var nameTrim = name.trim;
+
+console.log(nameTrim);
+
+//console.log(message);
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..1334c8c39 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,5 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+var numberOfStudents = 15;
+var numberOfMentors = 4;
+var sumNumber = numberOfStudents + numberOfMentors;
+console.log(sumNumber);
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..55be7ef36 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,11 @@
 var numberOfStudents = 15;
 var numberOfMentors = 8;
+var total = numberOfStudents + numberOfMentors;
+var studentPercentage = (numberOfStudents / total) * 100;
+var mentorsPercentage = (numberOfMentors / total) * 100;
+var studentsRoughNo = Math.round(studentPercentage);
+var mentorsRoughNo = Math.round(mentorsPercentage);
+var student = " student percentage is  " + studentsRoughNo + " %";
+var mentors = " mentors percentag is " + mentorsRoughNo + " %";
+console.log(student);
+console.log(mentors);
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..3c5ee6739 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,7 +1,8 @@
 function halve(number) {
+  return number / 2;
   // complete the function here
 }
 
-var result = halve(12);
+var result = halve(9);
 
 console.log(result);
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..75d1c2f90 100644
--- a/exercises/J-functions/exercise2.js
+++ b/exercises/J-functions/exercise2.js
@@ -1,4 +1,5 @@
 function triple(number) {
+  return number * 3;
   // complete function here
 }
 
diff --git a/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..c0a0f867c 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,7 +1,10 @@
 // Complete the function so that it takes input parameters
-function multiply() {
+// Complete the function so that it takes input parameters
+function multiply(num1, num2) {
   // Calculate the result of the function and return it
+  return num1 * num2;
 }
+multiply(3, 4);
 
 // Assign the result of calling the function the variable `result`
 var result = multiply(3, 4);
diff --git a/exercises/K-functions-parameters/exercise2.js b/exercises/K-functions-parameters/exercise2.js
index db7a8904b..0d0c4b3c0 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,4 +1,7 @@
 // Declare your function first
+function divide(num1, num2) {
+  return num1 / num2;
+}
 
 var result = divide(3, 4);
 
diff --git a/exercises/K-functions-parameters/exercise3.js b/exercises/K-functions-parameters/exercise3.js
index 537e9f4ec..aa1b150fb 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 my name is  " + name;
+}
 
 var greeting = createGreeting("Daniel");
 
diff --git a/exercises/K-functions-parameters/exercise4.js b/exercises/K-functions-parameters/exercise4.js
index 7ab44589e..f000ca360 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,4 +1,8 @@
 // Declare your function first
+function addNumbers(num1, num2) {
+  return num1 + num2;
+}
+var sum = addNumbers(13, 124);
 
 // Call the function and assign to a variable `sum`
 
diff --git a/exercises/K-functions-parameters/exercise5.js b/exercises/K-functions-parameters/exercise5.js
index 7c5bcd605..cca2405b2 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 "my name is Daniel and I'm " + age + " years old";
+}
 
 const greeting = createLongGreeting("Daniel", 30);
 
diff --git a/exercises/L-functions-nested/exercise.js b/exercises/L-functions-nested/exercise.js
index a5d377442..39c0d1c55 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -3,3 +3,22 @@ var mentor2 = "Irina";
 var mentor3 = "Mimi";
 var mentor4 = "Rob";
 var mentor5 = "Yohannes";
+//function 1//
+
+var mentors = ["Daniel", "Irina", "Mimi", "Rob", "Yohannes"];
+var names;
+for (var x = 0; x < mentors.length; x++) {
+  names = "hello " + mentors[x];
+  var greeting = names.toUpperCase();
+
+  console.log(greeting);
+}
+
+/* function 2
+function sayHello() {
+  var mentors = ["Daniel", "Irina", "Mimi", "Rob", "Yohannes"];
+  for (var x = 0; x < mentors.length; x++) {
+    var result = "hello" + callNames(x);
+  }
+  console.log(result);
+}*/
diff --git a/extra/1-currency-conversion.js b/extra/1-currency-conversion.js
index d82e59480..a71145f1d 100644
--- a/extra/1-currency-conversion.js
+++ b/extra/1-currency-conversion.js
@@ -5,8 +5,14 @@
   Write a function that converts a price to USD (exchange rate is 1.4 $ to £)
 */
 
-function convertToUSD() {}
-
+function convertToUSD(input) {
+
+  const exchangeRate = 1.4;
+  var USD = input * exchangeRate ;
+  return USD;
+}
+console.log(convertToUSD(32));
+// console.log(50);
 /*
   CURRENCY CONVERSION
   ===================
@@ -15,7 +21,14 @@ 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(inputStrling) {
+  
+  var afterCommession = inputStrling * 99;
+  var exchangeRate = 5.7;
+  var BRZreal = afterCommession * exchangeRate;
+  return BRZreal;
+}
+ console.log(convertToBRL(30));
 
 /* ======= 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 9c8ebc76a..4579d86ae 100644
--- a/extra/2-piping.js
+++ b/extra/2-piping.js
@@ -16,17 +16,26 @@
   the final result to the variable goodCode
 */
 
-function add() {
+function add(num1,num2) {
+  var Sum = num1 + num2;
+  return Sum;
 
 }
+console.log(Sum(2,4));
 
-function multiply() {
+function multiply( num1,num2) {
+  var multiply = num1 * num2;
+  return multiply;
 
 }
+console.log(multiply(5,6));
+
+function format(num) {
+  return `£ ${num}`;
 
-function format() {
 
 }
+console.log(format(num));
 
 const startingValue = 2;
 
diff --git a/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index a10cc9ac2..524729e81 100644
--- a/mandatory/1-syntax-errors.js
+++ b/mandatory/1-syntax-errors.js
@@ -1,17 +1,18 @@
 // There are syntax errors in this code - can you fix it to pass the tests?
 
-function addNumbers(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";
+  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;
 }
+let x ; 
 
 /* 
 ===================================================
diff --git a/mandatory/2-logic-error.js b/mandatory/2-logic-error.js
index 9cca7603b..db8e788b8 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 getStringLength(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 5a953ba60..3bd3c598b 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -1,14 +1,17 @@
 // Add comments to explain what this function does. You're meant to use Google!
 function getRandomNumber() {
+  // take a random number and time it by 10
   return Math.random() * 10;
 }
 
 // Add comments to explain what this function does. You're meant to use Google!
 function combine2Words(word1, word2) {
+  // add word1 and word2
   return word1.concat(word2);
 }
 
 function concatenate(firstWord, secondWord, thirdWord) {
+  return "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.
 }
diff --git a/mandatory/4-tax.js b/mandatory/4-tax.js
index ba77c7ae2..433135363 100644
--- a/mandatory/4-tax.js
+++ b/mandatory/4-tax.js
@@ -5,7 +5,12 @@
   Sales tax is 20% of the price of the product.
 */
 
-function calculateSalesTax() {}
+function calculateSalesTax(price) {
+ 
+  var tax = (20 * price) / 100;
+  final = tax + price;
+  return final;
+}
 
 /*
   CURRENCY FORMATTING
@@ -17,7 +22,12 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function addTaxAndFormatCurrency() {}
+function addTaxAndFormatCurrency() {
+  const priceWithTax = calculateSalesTax(price);
+  const formattedPrice = '£' + priceWithTax.toFixed(2);
+  return formattedPrice;
+}
+}
 
 /* 
 ===================================================
diff --git a/package.json b/package.json
index 58555936d..778df9683 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,9 @@
     "url": "https://github.com/CodeYourFuture/JavaScript-Core-1-Coursework-Week1/issues"
   },
   "jest": {
-    "setupFilesAfterEnv": ["jest-extended"]
+    "setupFilesAfterEnv": [
+      "jest-extended"
+    ]
   },
   "homepage": "https://github.com/CodeYourFuture/JavaScript-Core-1-Coursework-Week1#readme",
   "devDependencies": {