diff --git a/week-1/1-exercises/B-hello-world/exercise.js b/week-1/1-exercises/B-hello-world/exercise.js
index b179ee9..4a05819 100644
--- a/week-1/1-exercises/B-hello-world/exercise.js
+++ b/week-1/1-exercises/B-hello-world/exercise.js
@@ -1 +1,2 @@
 console.log("Hello world");
+console.log("Java is fun");
\ No newline at end of file
diff --git a/week-1/1-exercises/C-variables/README.md b/week-1/1-exercises/C-variables/README.md
index 26eccc1..5230e5c 100644
--- a/week-1/1-exercises/C-variables/README.md
+++ b/week-1/1-exercises/C-variables/README.md
@@ -15,7 +15,7 @@ The program above will print "Hello world" to the console. Notice how it uses th
 * Add a variable `greeting` to exercise.js (make sure it comes _before_ the console.log)
 * Print your `greeting` to the console 3 times
 
-> Remember: to run this exercise you must change directory to the `D-variables`. If you already have a terminal window open for the previous exercise you can do this by running the command `cd ../D-variables`.
+> Remember: to run this exercise you must change directory to the `cd D-variables`. If you already have a terminal window open for the previous exercise you can do this by running the command `cd ../D-variables`.
 
 ## Expected result
 
diff --git a/week-1/1-exercises/C-variables/exercise.js b/week-1/1-exercises/C-variables/exercise.js
index a6bbb97..c06ad85 100644
--- a/week-1/1-exercises/C-variables/exercise.js
+++ b/week-1/1-exercises/C-variables/exercise.js
@@ -1,3 +1,6 @@
 // Start by creating a variable `greeting`
+let greeting ="Hello world"
 
 console.log(greeting);
+console.log(greeting);
+console.log(greeting);
diff --git a/week-1/1-exercises/D-strings/exercise.js b/week-1/1-exercises/D-strings/exercise.js
index 2cffa6a..37c19ad 100644
--- a/week-1/1-exercises/D-strings/exercise.js
+++ b/week-1/1-exercises/D-strings/exercise.js
@@ -1,3 +1,7 @@
 // Start by creating a variable `message`
 
+let message = "Some string";
+let messagetype = typeof message;
 console.log(message);
+console.log(messagetype);
+
diff --git a/week-1/1-exercises/E-strings-concatenation/exercise.js b/week-1/1-exercises/E-strings-concatenation/exercise.js
index 2cffa6a..23cc2b6 100644
--- a/week-1/1-exercises/E-strings-concatenation/exercise.js
+++ b/week-1/1-exercises/E-strings-concatenation/exercise.js
@@ -1,3 +1,6 @@
 // Start by creating a variable `message`
+var greeting = 'Hello, my name is ';
+var firstName = 'Hussein';
+var intro = greeting + firstName 
 
-console.log(message);
+console.log(intro);
diff --git a/week-1/1-exercises/F-strings-methods/exercise.js b/week-1/1-exercises/F-strings-methods/exercise.js
index 2cffa6a..2be79f8 100644
--- a/week-1/1-exercises/F-strings-methods/exercise.js
+++ b/week-1/1-exercises/F-strings-methods/exercise.js
@@ -1,3 +1,6 @@
 // Start by creating a variable `message`
+var name = "Hussein";
+var namelength = name.length;
+console.log("My name is Hussein and my name is " + name.length + " characters long" );
+
 
-console.log(message);
diff --git a/week-1/1-exercises/F-strings-methods/exercise2.js b/week-1/1-exercises/F-strings-methods/exercise2.js
index b4b4694..d95cf78 100644
--- a/week-1/1-exercises/F-strings-methods/exercise2.js
+++ b/week-1/1-exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,4 @@
-const name = " Daniel  ";
-
-console.log(message);
+const name = " Hussein";
+var namelength = name.length;
+var message = "My name is Hussein and my name is " + name.length + " characters long";
+console.log(message.trim() );
diff --git a/week-1/1-exercises/G-numbers/exercise.js b/week-1/1-exercises/G-numbers/exercise.js
index 49e7bc0..66a4ecb 100644
--- a/week-1/1-exercises/G-numbers/exercise.js
+++ b/week-1/1-exercises/G-numbers/exercise.js
@@ -1 +1,8 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+var numberOfStudents = 15;
+var numberOfMentors = 8;
+var sum = numberOfStudents + numberOfMentors;
+console.log("Number of students: " + numberOfStudents);
+console.log("Number of mentors: " + numberOfMentors);
+console.log("Total numnber of students and mentors: " + sum);
+
diff --git a/week-1/1-exercises/I-floats/exercise.js b/week-1/1-exercises/I-floats/exercise.js
index a5bbcd8..5106afb 100644
--- a/week-1/1-exercises/I-floats/exercise.js
+++ b/week-1/1-exercises/I-floats/exercise.js
@@ -1,2 +1,8 @@
 var numberOfStudents = 15;
 var numberOfMentors = 8;
+var sum = numberOfStudents + numberOfMentors;
+var studentPercentage = Math.round((numberOfStudents/sum) * 100);
+var mentorsPercentage = Math.round((numberOfMentors/sum) * 100);
+
+console.log("Percentage students: " + studentPercentage + "%");
+console.log("Percentage mentors: " + mentorsPercentage + "%");
diff --git a/week-1/1-exercises/J-functions/exercise.js b/week-1/1-exercises/J-functions/exercise.js
index 0ae5850..a62cdfb 100644
--- a/week-1/1-exercises/J-functions/exercise.js
+++ b/week-1/1-exercises/J-functions/exercise.js
@@ -1,5 +1,5 @@
 function halve(number) {
-  // complete the function here
+ return number/2
 }
 
 var result = halve(12);
diff --git a/week-1/1-exercises/J-functions/exercise2.js b/week-1/1-exercises/J-functions/exercise2.js
index 82ef5e7..a70b80b 100644
--- a/week-1/1-exercises/J-functions/exercise2.js
+++ b/week-1/1-exercises/J-functions/exercise2.js
@@ -1,5 +1,5 @@
 function triple(number) {
-  // complete function here
+ return number * 3;
 }
 
 var result = triple(12);
diff --git a/week-1/1-exercises/K-functions-parameters/exercise.js b/week-1/1-exercises/K-functions-parameters/exercise.js
index 8d5db5e..62e7148 100644
--- a/week-1/1-exercises/K-functions-parameters/exercise.js
+++ b/week-1/1-exercises/K-functions-parameters/exercise.js
@@ -1,6 +1,6 @@
 // Complete the function so that it takes input parameters
-function multiply() {
-  // Calculate the result of the function and return it
+function multiply(a,b) {
+  return a * b;
 }
 
 // Assign the result of calling the function the variable `result`
diff --git a/week-1/1-exercises/K-functions-parameters/exercise2.js b/week-1/1-exercises/K-functions-parameters/exercise2.js
index db7a890..8b522f6 100644
--- a/week-1/1-exercises/K-functions-parameters/exercise2.js
+++ b/week-1/1-exercises/K-functions-parameters/exercise2.js
@@ -1,4 +1,7 @@
 // Declare your function first
+function divide(a,b){
+    return a / b;
+}
 
 var result = divide(3, 4);
 
diff --git a/week-1/1-exercises/K-functions-parameters/exercise3.js b/week-1/1-exercises/K-functions-parameters/exercise3.js
index 537e9f4..de0c53a 100644
--- a/week-1/1-exercises/K-functions-parameters/exercise3.js
+++ b/week-1/1-exercises/K-functions-parameters/exercise3.js
@@ -1,5 +1,8 @@
 // Write your function here
+function createGreeting(name){
+    return "Hello, my name is " + name;
+}
 
-var greeting = createGreeting("Daniel");
+var greeting = createGreeting("Hussein");
 
 console.log(greeting);
diff --git a/week-1/1-exercises/K-functions-parameters/exercise4.js b/week-1/1-exercises/K-functions-parameters/exercise4.js
index 7ab4458..acac982 100644
--- a/week-1/1-exercises/K-functions-parameters/exercise4.js
+++ b/week-1/1-exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,8 @@
 // Declare your function first
-
+function addation(a,b){
+    return a + b;
+}
+var sum = addation(13,124);
 // Call the function and assign to a variable `sum`
 
 console.log(sum);
diff --git a/week-1/1-exercises/K-functions-parameters/exercise5.js b/week-1/1-exercises/K-functions-parameters/exercise5.js
index 7c5bcd6..881359d 100644
--- a/week-1/1-exercises/K-functions-parameters/exercise5.js
+++ b/week-1/1-exercises/K-functions-parameters/exercise5.js
@@ -1,5 +1,8 @@
 // Declare your function here
+function createLongGreeting(name,age){
+    return "Hello, my name is " + name + " and I'm " + age + " years old";
+}
 
-const greeting = createLongGreeting("Daniel", 30);
+const greeting = createLongGreeting("Hussein", 30);
 
 console.log(greeting);
diff --git a/week-1/1-exercises/L-functions-nested/exercise.js b/week-1/1-exercises/L-functions-nested/exercise.js
index a5d3774..f8b03c0 100644
--- a/week-1/1-exercises/L-functions-nested/exercise.js
+++ b/week-1/1-exercises/L-functions-nested/exercise.js
@@ -1,5 +1,22 @@
-var mentor1 = "Daniel";
-var mentor2 = "Irina";
-var mentor3 = "Mimi";
-var mentor4 = "Rob";
-var mentor5 = "Yohannes";
+
+//Calculating the percentage of students
+function percentStdts(numOfStudents){
+    return Math.round(numOfStudents / 23 * 100);
+}
+function message(numOfStudents){
+    var value = percentStdts(numOfStudents);
+    return "Percentage of students: " + value + "%";
+}
+console.log(message(15));
+
+   //Calculating the percentage of mentors
+function percentMentors(numOfMentors){
+    return Math.round(numOfMentors / 23 * 100);
+}
+function mentorsMessage(numOfMentors){
+    var mentorsValue = percentMentors(numOfMentors);
+    return "Percentage of students: " + mentorsValue + "%";
+}
+console.log(mentorsMessage(8));
+
+
diff --git a/week-1/2-mandatory/1-syntax-errors.js b/week-1/2-mandatory/1-syntax-errors.js
index 6910f28..7c408ae 100644
--- a/week-1/2-mandatory/1-syntax-errors.js
+++ b/week-1/2-mandatory/1-syntax-errors.js
@@ -2,19 +2,20 @@
 
 // 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";
+function introduceMe(name, age) {
+return `Hello, my name is ${name} and I am ${age} years old`;
+}
 
-function getAddition(a, b) {
-    total = a ++ b
+ function getRemainder(a, b) {
+   var remainder = a % b;
 
-    // Use string interpolation here
-    return "The total is %{total}"
-}
+     
+     return `The remainder is ${remainder}`;
+ }
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 // 
diff --git a/week-1/2-mandatory/2-logic-error.js b/week-1/2-mandatory/2-logic-error.js
index 1e0a9d4..abe2cf9 100644
--- a/week-1/2-mandatory/2-logic-error.js
+++ b/week-1/2-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;
 }
 
 /* ======= TESTS - DO NOT MODIFY ===== 
diff --git a/week-1/2-mandatory/3-function-output.js b/week-1/2-mandatory/3-function-output.js
index bbb88a2..5ba717e 100644
--- a/week-1/2-mandatory/3-function-output.js
+++ b/week-1/2-mandatory/3-function-output.js
@@ -1,14 +1,23 @@
 // Add comments to explain what this function does. You're meant to use Google!
+
+/* This is a random numbers generating function that give a random number between 
+ 0 and 9 (both included). */
 function getNumber() {
   return Math.random() * 10;
 }
 
 // Add comments to explain what this function does. You're meant to use Google!
+
+/* This is a method used to combine arrays into one array. The array before concat() (w1) will be placed first in the 
+new array. And the array inside the parenthesis (w2) will be placed last. */
 function s(w1, w2) {
   return w1.concat(w2);
 }
 
 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 to expect in return
 }
diff --git a/week-1/2-mandatory/4-tax.js b/week-1/2-mandatory/4-tax.js
index 6b84208..f92580f 100644
--- a/week-1/2-mandatory/4-tax.js
+++ b/week-1/2-mandatory/4-tax.js
@@ -5,7 +5,11 @@
   Sales tax is 20% of the price of the product
 */
 
-function calculateSalesTax() {}
+function calculateSalesTax(price) {
+  var priceAfterTax = (price * 0.2) + price;
+  return priceAfterTax;
+
+}
 
 /*
   CURRENCY FORMATTING
@@ -17,7 +21,10 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function formatCurrency() {}
+function formatCurrency(price) {
+  var  finalPrice = calculateSalesTax(price);
+  return `£${finalPrice.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/week-1/3-extra/1-currency-conversion.js b/week-1/3-extra/1-currency-conversion.js
index 7f321d9..fa4bb3b 100644
--- a/week-1/3-extra/1-currency-conversion.js
+++ b/week-1/3-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(pounds) {
+  return pounds * 1.4;
+}
 
 /*
   CURRENCY FORMATTING
@@ -16,7 +18,9 @@ function convertToUSD() {}
   Find a way to add 1% to all currency conversions (think about the DRY principle)
 */
 
-function convertToBRL() {}
+function convertToBRL(pound) {
+  return (pound * 5.7) * 1.01;
+}
 
 /* ======= 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/week-1/3-extra/2-piping.js b/week-1/3-extra/2-piping.js
index 93c0bf7..52d2995 100644
--- a/week-1/3-extra/2-piping.js
+++ b/week-1/3-extra/2-piping.js
@@ -16,22 +16,25 @@
   the final result to the variable goodCode
 */
 
-function add() {
-
+function add(a, b) {
+return a + b;
 }
 
-function multiply() {
-
+function multiply(c, d) {
+return c * d;
 }
 
-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 = 
+let badCode = format(multiply(add(startingValue, 10), 2));
+
+
 
 /* BETTER PRACTICE */