diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..23a990095 100644
--- a/exercises/B-hello-world/exercise.js
+++ b/exercises/B-hello-world/exercise.js
@@ -1 +1,3 @@
+//noconsole.log("Hello world");
 console.log("Hello world");
+
diff --git a/exercises/C-variables/README.md b/exercises/C-variables/README.md
index 40859b3a8..0762650c9 100644
--- a/exercises/C-variables/README.md
+++ b/exercises/C-variables/README.md
@@ -5,6 +5,8 @@ We can use _variable_ to create a reference to a value.
 ```js
 var greeting = "Hello world";
 
+console.log(greeting);
+console.log(greeting);
 console.log(greeting);
 ```
 
diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..3244c32f2 100644
--- a/exercises/C-variables/exercise.js
+++ b/exercises/C-variables/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `greeting`
-
+var greeting = "Hello World";
+console.log(greeting);
+console.log(greeting);
 console.log(greeting);
diff --git a/exercises/D-strings/exercise.js b/exercises/D-strings/exercise.js
index 2cffa6a81..f3bb9edd6 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,4 @@
 // Start by creating a variable `message`
-
+let message = "This is a string";
 console.log(message);
+console.log(typeof message);
diff --git a/exercises/E-strings-concatenation/exercise.js b/exercises/E-strings-concatenation/exercise.js
index 2cffa6a81..c493f0800 100644
--- a/exercises/E-strings-concatenation/exercise.js
+++ b/exercises/E-strings-concatenation/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `message`
-
+let greeting = "Hello, "
+let myname = "My name is Shima"
+let message = greeting + myname;
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..3e56b07a4 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`
+let firstname = "shima";
+let nameLength = firstname.length;
+console.log(nameLength);
 
-console.log(message);
+ console.log ("My name is " + firstname +  " and it has " +  nameLength + " characters");
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..2f187834b 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,3 @@
 const name = " Daniel  ";
-
+let message = name.trim();
 console.log(message);
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..682f706cd 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,5 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+let numberOfStudents = 15;
+let numberOfMentors = 8;
+let sum = numberOfStudents + numberOfMentors;
+console.log(`Total number of the students and mentors: ${sum}`);
\ No newline at end of file
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..b3b63cb91 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,6 @@
 var numberOfStudents = 15;
 var numberOfMentors = 8;
+var precentageOfStudents = (numberOfStudents / (numberOfStudents + numberOfMentors))*100;
+var precentageOfMentors = (numberOfMentors / (numberOfStudents + numberOfMentors))*100;
+console.log(Math.round(precentageOfStudents));
+console.log(Math.round (precentageOfMentors));
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..1434589f6 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,7 +1,9 @@
 function halve(number) {
   // complete the function here
+  return number / 2;
 }
 
 var result = halve(12);
 
 console.log(result);
+console.log(halve(20));
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..831f3ce26 100644
--- a/exercises/J-functions/exercise2.js
+++ b/exercises/J-functions/exercise2.js
@@ -1,5 +1,6 @@
 function triple(number) {
   // complete function here
+  return 3 * number;
 }
 
 var result = triple(12);
diff --git a/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..71969d100 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,6 +1,7 @@
 // Complete the function so that it takes input parameters
-function multiply() {
+function multiply(num1,num2) {
   // Calculate the result of the function and return it
+  return num1 * num2;
 }
 
 // Assign the result of calling the function the variable `result`
diff --git a/exercises/K-functions-parameters/exercise2.js b/exercises/K-functions-parameters/exercise2.js
index db7a8904b..a6d6b6470 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..08918e1e4 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..44e3543d0 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,8 @@
 // Declare your function first
+function addTwonumbers(num1,num2){
+    return num1 + num2;
+}
 
 // Call the function and assign to a variable `sum`
-
+let sum = addTwonumbers(13,124);
 console.log(sum);
diff --git a/exercises/K-functions-parameters/exercise5.js b/exercises/K-functions-parameters/exercise5.js
index 7c5bcd605..3d55a9591 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/exercise.js b/exercises/L-functions-nested/exercise.js
index a5d377442..e027d3f8c 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -3,3 +3,11 @@ var mentor2 = "Irina";
 var mentor3 = "Mimi";
 var mentor4 = "Rob";
 var mentor5 = "Yohannes";
+function shoutyGreeting(name){
+    return "HELLO " + name.toUpperCase()
+}
+console.log(shoutyGreeting(mentor1));
+console.log(shoutyGreeting(mentor2));
+console.log(shoutyGreeting(mentor3));
+console.log(shoutyGreeting(mentor4));
+console.log(shoutyGreeting(mentor5));
diff --git a/extra/1-currency-conversion.js b/extra/1-currency-conversion.js
index 75b3c6aab..d9eca5f2f 100644
--- a/extra/1-currency-conversion.js
+++ b/extra/1-currency-conversion.js
@@ -5,7 +5,10 @@
   Write a function that converts a price to USD (exchange rate is 1.4 $ to £)
 */
 
-function convertToUSD() {}
+function convertToUSD(prices) {
+  return prices * 1.4;
+
+}
 
 /*
   CURRENCY CONVERSION
@@ -15,7 +18,9 @@ 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(prices) {
+  return 5.7 * (.99 * prices).toFixed(2);
+}
 
 /* ======= 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/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index a10cc9ac2..2772c4ab9 100644
--- a/mandatory/1-syntax-errors.js
+++ b/mandatory/1-syntax-errors.js
@@ -1,17 +1,22 @@
 // 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;
 }
+console.log(addNumbers(3,4,5));
 
-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";
+}
+console.log(introduceMe("Sima" , 35));
 
-function getTotal(a, b) {
-  total = a ++ b;
+ function getTotal(a, b) {
+   total = a + b;
 
-  return "The total is total";
-}
+  return "The total is " + total;
+ }
+
+ console.log(getTotal(23,5));
 
 /* 
 ===================================================
@@ -25,16 +30,16 @@ To run the tests for just this one file, type `npm test -- --testPathPattern 1-s
 ===================================================
 */
 
-test("addNumbers adds numbers correctly", () => {
-  expect(addNumbers(3, 4, 6)).toEqual(13);
-});
+// test("addNumbers adds numbers correctly", () => {
+//   expect(addNumbers(3, 4, 6)).toEqual(13);
+// });
 
-test("introduceMe function returns the correct string", () => {
-  expect(introduceMe("Sonjide", 27)).toEqual(
-    "Hello, my name is Sonjide and I am 27 years old"
-  );
-});
+// test("introduceMe function returns the correct string", () => {
+//   expect(introduceMe("Sonjide", 27)).toEqual(
+//     "Hello, my name is Sonjide and I am 27 years old"
+//   );
+// });
 
-test("getTotal returns a string describing the total", () => {
-  expect(getTotal(23, 5)).toEqual("The total is 28");
-});
+// test("getTotal returns a string describing the total", () => {
+//   expect(getTotal(23, 5)).toEqual("The total is 28");
+// });
diff --git a/mandatory/2-logic-error.js b/mandatory/2-logic-error.js
index 9cca7603b..2794f7348 100644
--- a/mandatory/2-logic-error.js
+++ b/mandatory/2-logic-error.js
@@ -1,17 +1,20 @@
 // The syntax for this function is valid but it has an error, find it and fix it.
 
 function trimWord(word) {
-  return wordtrim();
-}
-
-function getStringLength(word) {
-  return "word".length();
+  return word.trim();
 }
+console.log(trimWord("   CodeYourFuture "));
 
+ function getStringLength(word) {
+  return word.length;
+ }
+console.log(trimWord(" CodeYourFuture teaches coding     "));
 function multiply(a, b, c) {
-  a * b * c;
-  return;
-}
+    return a * b * c;
+  
+ }
+ console.log(multiply(3,5,7));
+ console.log(getStringLength("Hello I am working"));
 
 /* 
 ===================================================
@@ -24,28 +27,28 @@ To run the tests for just this one file, type `npm test -- --testPathPattern 2-l
 ===================================================
 */
 
-test("trimWord trims leading and trailing whitespace", () => {
-  expect(trimWord("   CodeYourFuture ")).toEqual("CodeYourFuture");
-});
+// test("trimWord trims leading and trailing whitespace", () => {
+//   expect(trimWord("   CodeYourFuture ")).toEqual("CodeYourFuture");
+// });
 
-test("trimWord doesn't remove whitespace in the middle of the string", () => {
-  expect(trimWord(" CodeYourFuture teaches coding     ")).toEqual(
-    "CodeYourFuture teaches coding"
-  );
-});
+// test("trimWord doesn't remove whitespace in the middle of the string", () => {
+//   expect(trimWord(" CodeYourFuture teaches coding     ")).toEqual(
+//     "CodeYourFuture teaches coding"
+//   );
+// });
 
-test("getStringLength returns the length of a word", () => {
-  expect(getStringLength("Turtles")).toEqual(7);
-});
+// test("getStringLength returns the length of a word", () => {
+//   expect(getStringLength("Turtles")).toEqual(7);
+// });
 
-test("getStringLength returns the length of a sentence", () => {
-  expect(getStringLength("A wild sentence appeared!")).toEqual(25);
-});
+// test("getStringLength returns the length of a sentence", () => {
+//   expect(getStringLength("A wild sentence appeared!")).toEqual(25);
+// });
 
-test("multiply multiplies numbers", () => {
-  expect(multiply(2, 3, 6)).toEqual(36);
-});
+// test("multiply multiplies numbers", () => {
+//   expect(multiply(2, 3, 6)).toEqual(36);
+// });
 
-test("multiply multiplies different numbers", () => {
-  expect(multiply(2, 3, 4)).toEqual(24);
-});
+// test("multiply multiplies different numbers", () => {
+//   expect(multiply(2, 3, 4)).toEqual(24);
+// });
diff --git a/mandatory/3-function-output.js b/mandatory/3-function-output.js
index 5a953ba60..bb6348625 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -1,13 +1,16 @@
 // Add comments to explain what this function does. You're meant to use Google!
+// This Function uses the Math random function to choose a random number bbetween zero and one and
+//then multiply it by  10.
 function getRandomNumber() {
   return Math.random() * 10;
 }
 
 // Add comments to explain what this function does. You're meant to use Google!
+//This Function combine the frist and second parameter which they both are strings.
 function combine2Words(word1, word2) {
   return word1.concat(word2);
 }
-
+//This function concatenate all the parameters which they can be string or numbers.
 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.
diff --git a/mandatory/4-tax.js b/mandatory/4-tax.js
index ba77c7ae2..cab74aaf0 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(price) {
+  return price * 1.2;
+}
+console.log(calculateSalesTax(17.5));
 
 /*
   CURRENCY FORMATTING
@@ -17,7 +20,10 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function addTaxAndFormatCurrency() {}
+function addTaxAndFormatCurrency(price) {
+  return "£" + calculateSalesTax(price).toFixed(2) ;
+}
+console.log( addTaxAndFormatCurrency(17.5));
 
 /* 
 ===================================================
@@ -34,6 +40,7 @@ test("calculateSalesTax for £15", () => {
   expect(calculateSalesTax(15)).toEqual(18);
 });
 
+
 test("calculateSalesTax for £17.50", () => {
   expect(calculateSalesTax(17.5)).toEqual(21);
 });
diff --git a/package.json b/package.json
index 93e0861e3..9e7f2ffeb 100644
--- a/package.json
+++ b/package.json
@@ -14,15 +14,21 @@
     "url": "https://github.com/CodeYourFuture/JavaScript-Core-1-Coursework-Week1/issues"
   },
   "jest": {
-    "setupFilesAfterEnv": ["jest-extended"],
+    "setupFilesAfterEnv": [
+      "jest-extended"
+    ],
     "projects": [
       {
         "displayName": "mandatory",
-        "testMatch": ["<rootDir>/mandatory/*.js"]
+        "testMatch": [
+          "<rootDir>/mandatory/*.js"
+        ]
       },
       {
         "displayName": "extra",
-        "testMatch": ["<rootDir>/extra/*.js"]
+        "testMatch": [
+          "<rootDir>/extra/*.js"
+        ]
       }
     ]
   },