diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..5afdeb3e0 100644
--- a/exercises/C-variables/exercise.js
+++ b/exercises/C-variables/exercise.js
@@ -1,3 +1,8 @@
 // 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..2361588d4 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 = "This is a string message.";
+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..183b72ab7 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`
+var greeting = "Hello, my name is ";
+var name = "Kate.";
+var message = greeting + name;
 
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..08ed52a0a 100644
--- a/exercises/F-strings-methods/exercise.js
+++ b/exercises/F-strings-methods/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `message`
 
+var message = "My name is Kate and my name is 4 characters long.";
+
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..9d23f8f09 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,5 @@
-const name = " Daniel  ";
+const name = "  My name is Kate and my name is 4 characters long  ";
+var nameTrim = name.trim;
+
+console.log(nameTrim);
 
-console.log(message);
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..e1dd35836 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,14 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+var numberOfStudents = 15;
+var numberOfMentors = 8;
+var totalNumberOfStudents = 23;
+
+var message =
+  "Number of students:" +
+  numberOfStudents +
+  "Number of mentors:" +
+  numberOfMentors +
+  "Total number of mentors and students:" +
+  totalNumberOfStudents;
+
+console.log(message);
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..ebcec1ebe 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,23 @@
 var numberOfStudents = 15;
 var numberOfMentors = 8;
+var totalNumber = 23;
+
+const quotient = numberOfStudents / totalNumber;
+const product = quotient * 100;
+
+console.log(product);
+
+const quotientTwo = numberOfMentors / totalNumber;
+const productTwo = quotientTwo * 100;
+
+console.log(productTwo);
+
+var precisePercentage = product;
+var roughPercentage = Math.round(precisePercentage);
+
+console.log(roughPercentage);
+
+var precisePercentageTwo = productTwo;
+var roughPercentageTwo = Math.round(precisePercentageTwo);
+
+console.log(roughPercentageTwo);
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..e7278f7bd 100644
--- a/exercises/J-functions/exercise.js
+++ b/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/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..95ef62512 100644
--- a/exercises/J-functions/exercise2.js
+++ b/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/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..62e71488e 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/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/exercises/K-functions-parameters/exercise2.js b/exercises/K-functions-parameters/exercise2.js
index db7a8904b..f654cc9d6 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,5 +1,8 @@
-// Declare your function first
+function divide(a, b) {
+  return a / b;
+}
 
 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..bed59804f 100644
--- a/exercises/K-functions-parameters/exercise3.js
+++ b/exercises/K-functions-parameters/exercise3.js
@@ -1,4 +1,6 @@
-// Write your function here
+function createGreeting(name) {
+  return "Hello, my name is " + name;
+}
 
 var greeting = createGreeting("Daniel");
 
diff --git a/exercises/K-functions-parameters/exercise4.js b/exercises/K-functions-parameters/exercise4.js
index 7ab44589e..78bef5f7e 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,10 @@
 // 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..ac09ff710 100644
--- a/exercises/K-functions-parameters/exercise5.js
+++ b/exercises/K-functions-parameters/exercise5.js
@@ -1,5 +1,9 @@
 // Declare your function here
 
+function createLongGreeting(name, number) {
+  return "Hello, my name is " + name + " and I'm " + number + " 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..9ec119b33 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -3,3 +3,21 @@ var mentor2 = "Irina";
 var mentor3 = "Mimi";
 var mentor4 = "Rob";
 var mentor5 = "Yohannes";
+
+function shoutyGreeting(greeting, name) {
+  var nameUpperCase = name.toUpperCase();
+  return greeting + nameUpperCase;
+}
+
+const mentorsGreeting = shoutyGreeting("HELLO ", mentor1);
+const mentorsGreeting2 = shoutyGreeting("HELLO ", mentor2);
+const mentorsGreeting3 = shoutyGreeting("HELLO ", mentor3);
+const mentorsGreeting4 = shoutyGreeting("HELLO ", mentor4);
+const mentorsGreeting5 = shoutyGreeting("HELLO ", mentor5);
+
+console.log(mentorsGreeting);
+console.log(mentorsGreeting2);
+console.log(mentorsGreeting3);
+console.log(mentorsGreeting4);
+console.log(mentorsGreeting5);
+
diff --git a/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index a10cc9ac2..98360ac6b 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;
+  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..f00d8bab3 100644
--- a/mandatory/2-logic-error.js
+++ b/mandatory/2-logic-error.js
@@ -5,14 +5,12 @@ function trimWord(word) {
 }
 
 function getStringLength(word) {
-  return "word".length();
+  return word.length();
 }
 
 function multiply(a, b, c) {
-  a * b * c;
-  return;
+  return a * b * c;
 }
-
 /* 
 ===================================================
 ======= TESTS - DO NOT MODIFY BELOW THIS LINE =====
diff --git a/mandatory/3-function-output.js b/mandatory/3-function-output.js
index 5a953ba60..30a945625 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -2,15 +2,16 @@
 function getRandomNumber() {
   return Math.random() * 10;
 }
+// Function getRandomNumber between 0 and 1 and multiplies it by 10. //
 
 // Add comments to explain what this function does. You're meant to use Google!
 function combine2Words(word1, word2) {
   return word1.concat(word2);
 }
+//This function is used to connect strings together into one new string. //
 
 function concatenate(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.
+  return firstWord.concat(secondWord, thirdWord);
 }
 
 /* 
diff --git a/mandatory/4-tax.js b/mandatory/4-tax.js
index ba77c7ae2..b21b100ee 100644
--- a/mandatory/4-tax.js
+++ b/mandatory/4-tax.js
@@ -5,7 +5,14 @@
   Sales tax is 20% of the price of the product.
 */
 
-function calculateSalesTax() {}
+function calculateSalesTax(price) {
+  return price * 1.2;
+}
+
+console.log(calculateSalesTax(15));
+console.log(calculateSalesTax(17.50));
+console.log(calculateSalesTax(34));
+
 
 /*
   CURRENCY FORMATTING
@@ -17,7 +24,14 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function addTaxAndFormatCurrency() {}
+function addTaxAndFormatCurrency(price) {
+  const totalPrice = calculateSalesTax;
+  return `£${totalPrice.toFixed(2)}`;
+}
+
+console.log(addTaxAndFormatCurrency(15));
+console.log(addTaxAndFormatCurrency(17.50));
+console.log(addTaxAndFormatCurrency(34));
 
 /* 
 ===================================================