diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..62084a9bf 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 World. I just started learning JavaScript!");
+console.log("Hello World. I just started learning JavaScript!");
\ No newline at end of file
diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..3c2e77c5b 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..3b8aaae1e 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `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..0e5d7ebfa 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`
-
-console.log(message);
+var greetingStart = "Hello, my name is ";
+var name = "Fatimoh";
+var greeting = greetingStart + name;
+console.log(greeting);
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..87cb6305f 100644
--- a/exercises/F-strings-methods/exercise.js
+++ b/exercises/F-strings-methods/exercise.js
@@ -1,3 +1,13 @@
 // Start by creating a variable `message`
+var name = "Fatimoh";
+var nameLength = name.length;  
+console.log(nameLength);
 
-console.log(message);
+var nameLowerCase = name.toLowerCase();
+console.log (nameLowerCase);
+
+var nameUpperCase = name.toUpperCase();
+console.log (nameUpperCase);
+
+var message = "My name is " + name + " and my name is " + nameLength + " characters long"
+console.log( message);
\ No newline at end of file
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..fe052d233 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,9 @@
-const name = " Daniel  ";
+var name = "Fatimoh";
+var nameLength = name.length;  
+console.log(nameLength);
 
-console.log(message);
+var nameTrim = name.trim;  
+console.log(name.trim("           Fatimoh        "));
+
+var message = "My name is " + name + " and my name is " + nameLength + " characters long"
+console.log( message);
\ No newline at end of file
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..7e9424225 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,7 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+var numberOfStudents = 18;
+var numberOfMentors = 5; 
+var total = numberOfStudents + numberOfMentors;
+console.log("Number of Students: " + numberOfStudents);
+console.log("Number of Mentors: " + numberOfMentors);
+console.log("Total Number of Students and Mentors: " + total);
\ No newline at end of file
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..006ed01d0 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,7 @@
 var numberOfStudents = 15;
 var numberOfMentors = 8;
+var total = numberOfStudents + numberOfMentors;
+var percentageOfStudents = (numberOfStudents / total) * 100;
+var percentageOfMentors = (numberOfMentors / total) * 100;
+console.log ("Percentage of Students: " + Math.round(percentageOfStudents) + "%"); 
+console.log ("Percentage of Mentors: " + Math.round(percentageOfMentors) + "%"); 
\ No newline at end of file
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..2ada77aed 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,7 +1,6 @@
 function halve(number) {
-  // complete the function here
+  return number / 2;
 }
-
 var result = halve(12);
-
 console.log(result);
+
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..7bfa8eb47 100644
--- a/exercises/J-functions/exercise2.js
+++ b/exercises/J-functions/exercise2.js
@@ -1,7 +1,5 @@
 function triple(number) {
-  // complete function here
+  return number * 3
 }
-
 var result = triple(12);
-
 console.log(result);
diff --git a/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..24c13958c 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,9 +1,5 @@
-// 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`
 var result = multiply(3, 4);
-
 console.log(result);
diff --git a/exercises/K-functions-parameters/exercise2.js b/exercises/K-functions-parameters/exercise2.js
index db7a8904b..03cd36673 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,4 +1,6 @@
-// Declare your function first
+function divide (a, b){
+    return a / b;
+}
 
 var result = divide(3, 4);
 
diff --git a/exercises/K-functions-parameters/exercise3.js b/exercises/K-functions-parameters/exercise3.js
index 537e9f4ec..13c575ce8 100644
--- a/exercises/K-functions-parameters/exercise3.js
+++ b/exercises/K-functions-parameters/exercise3.js
@@ -1,5 +1,6 @@
-// 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..01ca4c9af 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,7 @@
 // Declare your function first
-
+function add(a, b){
+    return a + b;
+}
 // 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..bfc2e46c5 100644
--- a/exercises/K-functions-parameters/exercise5.js
+++ b/exercises/K-functions-parameters/exercise5.js
@@ -1,5 +1,7 @@
 // Declare your function here
-
-const greeting = createLongGreeting("Daniel", 30);
+function createLongGreeting (name, age) {
+     return "Hello, my name is " + name + " and  I'm " + age + " years old";
+}
+   const greeting = createLongGreeting("Daniel", 30);
 
 console.log(greeting);
diff --git a/exercises/L-functions-nested/README.md b/exercises/L-functions-nested/README.md
index f5e571303..11597c986 100644
--- a/exercises/L-functions-nested/README.md
+++ b/exercises/L-functions-nested/README.md
@@ -9,7 +9,7 @@ function getAgeInDays(age) {
   return age * 365;
 }
 
-function createCreeting(name, age) {
+function createGreeting(name, age) {
   var ageInDays = getAgeInDays(age);
   var message =
     "My Name is " + name + " and I was born over " + ageInDays + " days ago!";
diff --git a/exercises/L-functions-nested/exercise.js b/exercises/L-functions-nested/exercise.js
index a5d377442..999d4caed 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -1,5 +1,65 @@
-var mentor1 = "Daniel";
-var mentor2 = "Irina";
-var mentor3 = "Mimi";
-var mentor4 = "Rob";
-var mentor5 = "Yohannes";
+var students = 15;
+var mentors = 8;
+function add (students, mentors) {
+    let  result = students + mentors;
+    return result;
+}
+console.log(add(students, mentors));
+
+function PercentageOfStudentAndMentor (students, mentors){
+    let result = add(students, mentors)
+    let studentPercentage = Math.round(students/ result *  100);
+    let mentorPercentage = Math.round (mentors / result * 100); 
+    return [studentPercentage, mentorPercentage];
+}
+    [percentage, stdPercent] = PercentageOfStudentAndMentor(students, mentors)
+
+    // console.log(PercentageOfStudentAndMentor(students, mentors));
+    console.log(percentage, stdPercent);
+
+ function message (students, mentors) {
+    [stdPercent, mentorPercentage] = PercentageOfStudentAndMentor(students, mentors)
+    let msg = "Percentage of students : " + stdPercent + "%";
+    let msg2 = " Percentage of mentors : " + mentorPercentage + "%";
+    return msg + msg2; 
+ }
+ console.log (message (students, mentors));
+
+ function upperCase(name) {
+    return name.toUpperCase()
+}
+ var mentors = ["daniel", "irina", "mimi", "rob", "yohannes"];
+    function shoutyG(name){
+        const capName = upperCase(name);
+        const message = "Hello, welcome " + capName + " to my world!";
+        return message;
+}
+for (let i=0; i < mentors.length; i++){
+    let mentorName = shoutyG
+    console.log(shoutyG(mentors[i]));
+}
+
+
+
+
+
+
+
+// var result = 8 / total * 100; 
+// console.log (Math.round(result));
+
+// var result2 = 15/ total * 100;
+// console.log (Math.round(result2));
+
+
+
+// function mentorNames ( nameUpperCase);
+//  return "Hello" + 
+
+// var nameUpperCase = name.toUpperCase();
+// console.log (nameUpperCase);
+// var mentor1 = "Daniel";
+// var mentor2 = "Irina";
+// var mentor3 = "Mimi";
+// var mentor4 = "Rob";
+// var mentor5 = "Yohannes";
diff --git a/extra/1-currency-conversion.js b/extra/1-currency-conversion.js
index 70a2fe863..d425697d1 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(currency) {
+  return currency * 1.4;
+}
 
 /*
   CURRENCY FORMATTING
@@ -15,7 +17,9 @@ 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(currency) {
+  return currency * (5.7) * 0.99;
+}
 
 /* ======= 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..bb0187231 100644
--- a/extra/2-piping.js
+++ b/extra/2-piping.js
@@ -16,8 +16,8 @@
   the final result to the variable goodCode
 */
 
-function add() {
-
+function add(a, b) {
+    return a + b;
 }
 
 function multiply() {
diff --git a/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index 0a21afd1b..576ef7f7d 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) {
+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;
+    var 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 3c578ad87..8b86078e2 100644
--- a/mandatory/2-logic-error.js
+++ b/mandatory/2-logic-error.js
@@ -1,17 +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 getWordLength(word) {
-  return "word".length();
+  return word.length;
 }
 
 function multiply(a, b, c) {
-  a * b * c;
-  return;
+   return a * b * c;
 }
+console.log (multiply());
 
 /* 
 ===================================================
diff --git a/mandatory/3-function-output.js b/mandatory/3-function-output.js
index c9221a200..dada473be 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -1,17 +1,24 @@
 // Add comments to explain what this function does. You're meant to use Google!
+// Maths.random will pick any random number between 0 and 1, excluding 1. 
+//* 10 means it would pick between 0 and 10, 10 exclusive.
 function getNumber() {
   return Math.random() * 10;
 }
 
 // Add comments to explain what this function does. You're meant to use Google!
+//This function add two parameters , w1 and w2 together.
 function s(w1, w2) {
   return w1.concat(w2);
 }
 
 function concatenate(firstWord, secondWord, thirdWord) {
+  return firstWord.concat(" ", 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 c9e41c691..e1c6d5830 100644
--- a/mandatory/4-tax.js
+++ b/mandatory/4-tax.js
@@ -5,8 +5,11 @@
   Sales tax is 20% of the price of the product
 */
 
-function calculateSalesTax() {}
-
+function calculateSalesTax(productPrice) {
+  let tax = 20 * productPrice / 100;
+  let totalSalePrice = productPrice + tax;
+  return totalSalePrice;
+}
 /*
   CURRENCY FORMATTING
   ===================
@@ -16,9 +19,12 @@ function calculateSalesTax() {}
 
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
-
-function addTaxAndFormatCurrency() {}
-
+function addTaxAndFormatCurrency(productPrice) {
+  let totalPrice = calculateSalesTax (productPrice);
+  let formatCurrency = totalPrice.toFixed(2);
+  return "£" + formatCurrency;
+}
+  
 /* 
 ===================================================
 ======= TESTS - DO NOT MODIFY BELOW THIS LINE =====