diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..a6b8c64d8 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..7cf8fab7a 100644
--- a/exercises/C-variables/exercise.js
+++ b/exercises/C-variables/exercise.js
@@ -1,3 +1,7 @@
 // Start by creating a variable `greeting`
+var greeting = "Hello world";
 
+
+console.log(greeting);
 console.log(greeting);
+console.log(greeting);
\ No newline at end of file
diff --git a/exercises/D-strings/exercise.js b/exercises/D-strings/exercise.js
index 2cffa6a81..3ec190237 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,7 @@
 // Start by creating a variable `message`
 
-console.log(message);
+var message = "This is a string";
+var messageType = typeof message;
+
+console.log(message); 
+console.log(messageType); 
\ No newline at end of file
diff --git a/exercises/E-strings-concatenation/exercise.js b/exercises/E-strings-concatenation/exercise.js
index 2cffa6a81..76d2ace0a 100644
--- a/exercises/E-strings-concatenation/exercise.js
+++ b/exercises/E-strings-concatenation/exercise.js
@@ -1,3 +1,7 @@
 // Start by creating a variable `message`
 
-console.log(message);
+var greetingStart = "Hello, my name is ";
+var name = "Abed";
+var greeting = greetingStart + name;
+
+console.log(greeting);
\ No newline at end of file
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..c0b29a7f3 100644
--- a/exercises/F-strings-methods/exercise.js
+++ b/exercises/F-strings-methods/exercise.js
@@ -1,3 +1,7 @@
 // Start by creating a variable `message`
+var name = "Abed   ";
+var nameLength = name.length;
+var nameLowerCase = name.trim().toLowerCase();
 
-console.log(message);
+
+console.log("My name is " + nameLowerCase + " and my name is " + nameLength + " characters long" ); 
\ No newline at end of file
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..4c4ee8192 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,6 @@
-const name = " Daniel  ";
+var name = "Abed   ";
+var nameLength = name.length;
+var nameLowerCase = name.trim().toLowerCase();
 
-console.log(message);
+
+console.log("My name is " + nameLowerCase + " and my name is " + nameLength + " characters long" )
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..c391e7b55 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,6 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+var numberOfStudents = 15 ;
+var numberOfMentors = 8 ;
+var sum = numberOfStudents + numberOfMentors
+//Total numnber of students and mentors: 23
+console.log("Total numnber of 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..1fc35bd82 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,11 @@
 var numberOfStudents = 15;
 var numberOfMentors = 8;
+var sum = numberOfStudents + numberOfMentors;
+
+var PercentageStudents =  numberOfStudents / sum ;
+var PercentageMentors = numberOfMentors / sum;
+
+
+console.log("Percentage students: " + Math.round(PercentageStudents*100) + "%")
+console.log("Percentage mentors: " + Math.round(PercentageMentors*100) + "%")
+
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..2f6173556 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,5 +1,6 @@
 function halve(number) {
   // complete the function here
+   return number / 2;
 }
 
 var result = halve(12);
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..6c13ce818 100644
--- a/exercises/J-functions/exercise2.js
+++ b/exercises/J-functions/exercise2.js
@@ -1,5 +1,6 @@
 function triple(number) {
   // complete function here
+   return number * 3;
 }
 
 var result = triple(12);
diff --git a/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..5d2bb0f9f 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,9 +1,43 @@
 // Complete the function so that it takes input parameters
-function multiply() {
+function multiply(x,y) {
   // Calculate the result of the function and return it
+  return x*y ;
 }
 
 // Assign the result of calling the function the variable `result`
 var result = multiply(3, 4);
 
 console.log(result);
+
+// Declare your function first
+function divide(x,y){
+
+    return x/y;
+}
+var result = divide(3, 4);
+console.log(result);
+
+
+// Write your function here
+function createGreeting(name) {
+  return "Hello, my name is " + name ;
+}
+var greeting = createGreeting("Daniel");
+console.log(greeting);
+
+
+// Declare your function first
+function addNum(x,y) {
+  return x+y ;
+}
+// Call the function and assign to a variable `sum`
+var sum = addNum(13,124);
+console.log(sum);
+
+
+function nameAge(name,age) {
+  return "Hello, my name is " + name +  " and I'm " + age + " years old" ;
+}
+// Call the function
+var greeting = nameAge("Daniel", 30);
+console.log(greeting);
\ No newline at end of file
diff --git a/exercises/K-functions-parameters/exercise2.js b/exercises/K-functions-parameters/exercise2.js
index db7a8904b..8d2d91602 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,4 +1,10 @@
 // Declare your function first
+function divide(x,y){
+
+    return x/y;
+}
+
+
 
 var result = divide(3, 4);
 
diff --git a/exercises/K-functions-parameters/exercise3.js b/exercises/K-functions-parameters/exercise3.js
index 537e9f4ec..fac2f4621 100644
--- a/exercises/K-functions-parameters/exercise3.js
+++ b/exercises/K-functions-parameters/exercise3.js
@@ -1,5 +1,7 @@
 // Write your function here
-
+function createGreeting(name) {
+  return "Hello, my name is " + name ;
+}
 var greeting = createGreeting("Daniel");
 
 console.log(greeting);
diff --git a/exercises/K-functions-parameters/exercise4.js b/exercises/K-functions-parameters/exercise4.js
index 7ab44589e..18f69f76f 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,9 @@
 // Declare your function first
+function addNum(x,y) {
+  return x+y ;
+}
 
 // Call the function and assign to a variable `sum`
+var sum = addNum(13,124);
 
-console.log(sum);
+console.log(sum);
\ No newline at end of file
diff --git a/exercises/K-functions-parameters/exercise5.js b/exercises/K-functions-parameters/exercise5.js
index 7c5bcd605..e632af09d 100644
--- a/exercises/K-functions-parameters/exercise5.js
+++ b/exercises/K-functions-parameters/exercise5.js
@@ -1,5 +1,9 @@
 // Declare your function here
+function addNum(name,age) {
+  return "Hello, my name is " + name +  " and I'm " + age + " years old" ;
+}
 
-const greeting = createLongGreeting("Daniel", 30);
+// Call the function
+var greeting = createLongGreeting("Daniel", 30);
 
 console.log(greeting);
diff --git a/exercises/L-functions-nested/exercise.js b/exercises/L-functions-nested/exercise.js
index a5d377442..8adb1bae7 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -3,3 +3,19 @@ var mentor2 = "Irina";
 var mentor3 = "Mimi";
 var mentor4 = "Rob";
 var mentor5 = "Yohannes";
+
+function hello(name) {
+  return "Hello " + name;
+}
+
+function createCreeting(name1, name2, name3, name4, name5) {
+  var message1 = hello(name1);
+  var message2 = hello(name2);
+  var message3 = hello(name3);
+  var message4 = hello(name4);
+  var message5 = hello(name5);
+  return message1 + message2 , message3, message4, message5;
+}
+
+var greeting =  createCreeting(mentor1, mentor2, mentor3, mentor4, mentor5);
+console.log(greeting);
\ No newline at end of file
diff --git a/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index a10cc9ac2..0f8045418 100644
--- a/mandatory/1-syntax-errors.js
+++ b/mandatory/1-syntax-errors.js
@@ -1,16 +1,16 @@
 // 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;
 }
 
 /* 
diff --git a/mandatory/2-logic-error.js b/mandatory/2-logic-error.js
index 9cca7603b..df2d78b26 100644
--- a/mandatory/2-logic-error.js
+++ b/mandatory/2-logic-error.js
@@ -1,16 +1,17 @@
 // 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..79d6a626f 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -1,14 +1,18 @@
 // Add comments to explain what this function does. You're meant to use Google!
+// Returns a random number times by 10
 function getRandomNumber() {
   return Math.random() * 10;
 }
 
 // Add comments to explain what this function does. You're meant to use Google!
+// count() function is used to count the number of collections in the element
 function combine2Words(word1, word2) {
   return word1.concat(word2);
 }
 
 function concatenate(firstWord, secondWord, thirdWord) {
+  return concat(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..b60fedf90 100644
--- a/mandatory/4-tax.js
+++ b/mandatory/4-tax.js
@@ -5,7 +5,9 @@
   Sales tax is 20% of the price of the product.
 */
 
-function calculateSalesTax() {}
+function calculateSalesTax(price) {
+  return price * 1.20;
+}
 
 /*
   CURRENCY FORMATTING
@@ -17,7 +19,9 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function addTaxAndFormatCurrency() {}
+function addTaxAndFormatCurrency(new_price) {
+  return concat ("£" + float(new_price * 1.20))
+}
 
 /* 
 ===================================================