diff --git a/exercises/B-hello-world/README.md b/exercises/B-hello-world/README.md
index 8c704fb43..99e7eff57 100644
--- a/exercises/B-hello-world/README.md
+++ b/exercises/B-hello-world/README.md
@@ -7,7 +7,7 @@ Inside of `exercise.js` there's a line of code that will print "Hello world!".
 ### 1. Run the program
 
 - Open a terminal window
-- Change directory to this folder (`cd B-hello-world`)
+- Change directory to this folder
 - Run the program using node (`node exercise.js`)
 
 ### 2. Experiment
diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..a65c38863 100644
--- a/exercises/B-hello-world/exercise.js
+++ b/exercises/B-hello-world/exercise.js
@@ -1 +1,9 @@
 console.log("Hello world");
+//Experiment
+console.log("Hello world. I just started learning Javascript!");
+console.log("This");
+console.log("is");
+console.log("a");
+console.log("drill.");
+
+console.log("hello world");//error shown when run without quotes. 
diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..63b0f28ce 100644
--- a/exercises/C-variables/exercise.js
+++ b/exercises/C-variables/exercise.js
@@ -1,3 +1,13 @@
 // Start by creating a variable `greeting`
-
+let greeting ='Hello world';
+console.log(greeting);
+console.log(greeting);
 console.log(greeting);
+
+// Alternative using loop?
+
+let greeting1 ='Hello world';
+
+for(let i = 0; i <3;i++) {
+    console.log(greeting1);
+}
\ No newline at end of file
diff --git a/exercises/D-strings/exercise.js b/exercises/D-strings/exercise.js
index 2cffa6a81..55ca9d5f5 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,6 @@
 // Start by creating a variable `message`
+let message ="This is my homework";
+let 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..00ae1a4bc 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`
+let greetingOpener = 'Hello my name is ';
+let myName = ' Donna.';
+let greeting = greetingOpener + myName;
 
-console.log(message);
+console.log(greeting);
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..ac36e9c21 100644
--- a/exercises/F-strings-methods/exercise.js
+++ b/exercises/F-strings-methods/exercise.js
@@ -1,3 +1,8 @@
 // Start by creating a variable `message`
+let myName ='Donna';
+let nameLength =myName.length
+console.log(myName.length);
 
-console.log(message);
+console.log(`My name is ${myName} and my name is ${myName.length} characters long.`);
+
+console.log(myName.trim);
\ No newline at end of file
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..801cfce80 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,3 @@
-const name = " Daniel  ";
+let yourName = " My name is Daniel and my name is 6 characters long  ";
 
-console.log(message);
+console.log(yourName.trim);
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..490f1db75 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,6 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+
+let numberOfStudents = 15;
+let numberOfMentors = 8;
+
+console.log(`There are ${numberOfStudents} students and ${numberOfMentors} mentors.`);
\ No newline at end of file
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..c1dda3f98 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,11 @@
-var numberOfStudents = 15;
-var numberOfMentors = 8;
+let numberOfStudents = 15;
+let numberOfMentors = 8;
+
+let total =numberOfStudents + numberOfMentors;
+console.log(`Total number of students and mentors: ${numberOfStudents + numberOfMentors}`);
+
+let percentageStudents =(100/total)*numberOfStudents;
+console.log(`Percentage of students: ${Math.round(percentageStudents)}%`);
+
+let percentageMentors=(100/total)*numberOfMentors;
+console.log(`Percentage of mentors: ${Math.round(percentageMentors)}%`);
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..3d62bf1b3 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,7 +1,8 @@
 function halve(number) {
-  // complete the function here
+  return number/2;
 }
 
-var result = halve(12);
+let result = halve(12);
 
 console.log(result);
+
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..40c9b3f88 100644
--- a/exercises/J-functions/exercise2.js
+++ b/exercises/J-functions/exercise2.js
@@ -1,7 +1,7 @@
 function triple(number) {
-  // complete function here
+  return number*3;
 }
 
-var result = triple(12);
+let result = triple(12);
 
 console.log(result);
diff --git a/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..62cabfe8e 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,9 +1,8 @@
 // Complete the function so that it takes input parameters
-function multiply() {
-  // Calculate the result of the function and return it
+function multiply(num1, num2) {
+  return num1 * num2;
 }
 
 // Assign the result of calling the function the variable `result`
-var result = multiply(3, 4);
-
+let 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..df40480a0 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,5 +1,9 @@
-// Declare your function first
 
-var result = divide(3, 4);
+function divide(Num1,Num2){
+return Num1/Num2;
+}
+let result = divide(3, 4);
 
 console.log(result);
+
+
diff --git a/exercises/K-functions-parameters/exercise3.js b/exercises/K-functions-parameters/exercise3.js
index 537e9f4ec..46d6a4a73 100644
--- a/exercises/K-functions-parameters/exercise3.js
+++ b/exercises/K-functions-parameters/exercise3.js
@@ -1,5 +1,12 @@
-// Write your function here
+//Write your function here
 
-var greeting = createGreeting("Daniel");
+function startGreet(name) {
+return "Hello, my name is " + name.;
+}
+let greeting = startGreet("Daniel")
 
 console.log(greeting);
+
+
+
+
diff --git a/exercises/K-functions-parameters/exercise4.js b/exercises/K-functions-parameters/exercise4.js
index 7ab44589e..e1f6f38e0 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,7 @@
 // Declare your function first
-
+function sum (num1,num2) {
+    return num1 + num2;
+}
 // Call the function and assign to a variable `sum`
 
-console.log(sum);
+console.log(sum(13, 124));
diff --git a/exercises/K-functions-parameters/exercise5.js b/exercises/K-functions-parameters/exercise5.js
index 7c5bcd605..890c585ff 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(nom, age) {
+    return `Hello, my name is ${nom} 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..e78516e06 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -1,5 +1,20 @@
-var mentor1 = "Daniel";
-var mentor2 = "Irina";
-var mentor3 = "Mimi";
-var mentor4 = "Rob";
-var mentor5 = "Yohannes";
+let mentor1 = " Daniel";
+let mentor2 = " Irina";
+let mentor3 = " Mimi";
+let mentor4 = " Rob";
+let mentor5 = " Yohannes";
+
+function shoutName (mentor) {
+    return mentor.toUpperCase();
+}
+
+function shoutGreeting (mentor) {
+    let greeting = 'HELLO';
+    return greeting  +  shoutName(mentor);
+}
+
+ console.log(shoutGreeting(mentor1));
+ console.log(shoutGreeting(mentor2));
+ console.log(shoutGreeting(mentor3));
+ console.log(shoutGreeting(mentor4));
+ console.log(shoutGreeting(mentor5));
diff --git a/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index a10cc9ac2..b47145379 100644
--- a/mandatory/1-syntax-errors.js
+++ b/mandatory/1-syntax-errors.js
@@ -1,16 +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";
+function introduceMe(name, age) {
+  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..b3436bbd1 100644
--- a/mandatory/2-logic-error.js
+++ b/mandatory/2-logic-error.js
@@ -1,16 +1,16 @@
 // 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..61835be48 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -2,17 +2,28 @@
 function getRandomNumber() {
   return Math.random() * 10;
 }
+//Math.random () returns a random number between 0 (inclusive ) and 1 (exclusive); (from W3 schools site)
 
 // Add comments to explain what this function does. You're meant to use Google!
 function combine2Words(word1, word2) {
   return word1.concat(word2);
 }
 
+//concat is a method that joins two or more strings (from W3 schools site)
+
+// 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.
+// }
+
+
 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.
 }
-
+//
 /* 
 ===================================================
 ======= TESTS - DO NOT MODIFY BELOW THIS LINE =====
diff --git a/mandatory/4-tax.js b/mandatory/4-tax.js
index ba77c7ae2..b6207f649 100644
--- a/mandatory/4-tax.js
+++ b/mandatory/4-tax.js
@@ -5,7 +5,11 @@
   Sales tax is 20% of the price of the product.
 */
 
-function calculateSalesTax() {}
+
+function calculateSalesTax(price) {
+let salesTax = 20;
+return price/100*20 
+}
 
 /*
   CURRENCY FORMATTING