diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 000000000..6b601e9a8
Binary files /dev/null and b/.DS_Store differ
diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..a147b8432 100644
--- a/exercises/B-hello-world/exercise.js
+++ b/exercises/B-hello-world/exercise.js
@@ -1 +1 @@
-console.log("Hello world");
+console.log("Hello great world ");
diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..f408e66c8 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"
 
 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..afacc7ac3 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,8 @@
 // Start by creating a variable `message`
+var message = "hello";
 
+
+var 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..1c53cb923 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`
+var greetingStart = "Hello, my name is ";
+var name = "Iwona";
 
-console.log(message);
+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..99409339f 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`
 
-console.log(message);
+var name = "Iwona";
+var nameLength = name.length;
+
+
+console.log("My name is Iwona and my name is " + nameLength + " characters long");
+
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..ebce343af 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,8 @@
-const name = " Daniel  ";
 
-console.log(message);
+
+const name = "Iwona ";
+const nameLength = name.length;
+const nameT = name.trim();
+
+
+console.log("My name is " + nameT + " and my name is " + nameLength + " characters long");
\ No newline at end of file
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..90c670bc2 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,11 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+
+
+
+
+let numberOfStudents = 15;
+let numberOfMentors = 8;
+let sum = numberOfStudents + numberOfMentors;
+
+
+console.log(sum);
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..7ed38521f 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,9 @@
 var numberOfStudents = 15;
 var numberOfMentors = 8;
+let sum = numberOfStudents + numberOfMentors;
+
+let x = (sum / numberOfStudents) * 100;
+let y = (sum / numberOfMentors) * 100;
+console.log(x);
+console.log(y);
+
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..99898ae3c 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,4 +1,5 @@
 function halve(number) {
+  return number / 2;
   // complete the function here
 }
 
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..468d45596 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..c34efd3d8 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,9 +1,11 @@
 // 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;  // Calculate the result of the function and return it
 }
 
 // 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..5aab370e4 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,5 +1,10 @@
 // Declare your function first
 
+function divide(num1, num2){
+    return num1 / num2;
+
+}
+
 var 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..33a019de1 100644
--- a/exercises/K-functions-parameters/exercise3.js
+++ b/exercises/K-functions-parameters/exercise3.js
@@ -1,5 +1,10 @@
-// Write your function here
+// Write your function here, Write a function that takes a name (a string) and returns a greeting
+
+function createGreeting(name){
+    return name;
+
+}
 
 var greeting = createGreeting("Daniel");
 
-console.log(greeting);
+console.log("Hello my name is "+ greeting);
diff --git a/exercises/K-functions-parameters/exercise4.js b/exercises/K-functions-parameters/exercise4.js
index 7ab44589e..6a9290ff2 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,11 @@
-// Declare your function first
+// Declare your function first 
 
 // Call the function and assign to a variable `sum`
 
+function add(num1, num2){
+    return num1 + num2;
+}
+
+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..9f8fae1ff 100644
--- a/exercises/K-functions-parameters/exercise5.js
+++ b/exercises/K-functions-parameters/exercise5.js
@@ -1,5 +1,13 @@
 // 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);
 
 console.log(greeting);
+
+
+
diff --git a/exercises/L-functions-nested/exercise.js b/exercises/L-functions-nested/exercise.js
index a5d377442..7d8acba18 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -3,3 +3,32 @@ var mentor2 = "Irina";
 var mentor3 = "Mimi";
 var mentor4 = "Rob";
 var mentor5 = "Yohannes";
+
+
+
+
+function upper(name){
+   return name.toUpperCase();
+ 
+}
+var upperCaseMentor1 = upper(mentor1);
+var upperCaseMentor2 = upper(mentor2);
+var upperCaseMentor3 = upper(mentor3);
+var upperCaseMentor4 = upper(mentor4);
+var upperCaseMentor5 = upper(mentor5);
+
+
+console.log("HELLO " + upperCaseMentor1);
+console.log("HELLO " + upperCaseMentor2);
+console.log("HELLO " + upperCaseMentor3);
+console.log("HELLO " + upperCaseMentor4);
+console.log("HELLO " + upperCaseMentor5);
+
+
+
+
+
+
+
+
+
diff --git a/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index a10cc9ac2..c0ec00ea2 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";
-
+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..37c4ebc15 100644
--- a/mandatory/2-logic-error.js
+++ b/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 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..053d1f63c 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -1,14 +1,17 @@
 // Add comments to explain what this function does. You're meant to use Google!
 function getRandomNumber() {
-  return Math.random() * 10;
+  return Math.random() * 10; // function returns a floating-point, pseudo-random number
 }
 
 // Add comments to explain what this function does. You're meant to use Google!
 function combine2Words(word1, word2) {
-  return word1.concat(word2);
+  return word1.concat(word2); //  method joins two or more strings
 }
 
 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 ba77c7ae2..f3c4c05a0 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(num) {
+  var tax = num * 0.2;
+  return num + tax;
+
+}
 
 /*
   CURRENCY FORMATTING
@@ -17,7 +21,16 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function addTaxAndFormatCurrency() {}
+function addTaxAndFormatCurrency(num) {
+  var tax = num * 0.2;
+  var price = num + tax;
+  var roundPrice = price.toFixed(2);
+  return "£" + roundPrice;
+  
+
+
+
+}
 
 /* 
 ===================================================