diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..e5528587e 100644
--- a/exercises/B-hello-world/exercise.js
+++ b/exercises/B-hello-world/exercise.js
@@ -1 +1,2 @@
 console.log("Hello world");
+console.log("I am officially a programmer");
diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..592348fed 100644
--- a/exercises/C-variables/exercise.js
+++ b/exercises/C-variables/exercise.js
@@ -1,3 +1,3 @@
 // Start by creating a variable `greeting`
-
+var greeting = "Hello";
 console.log(greeting);
diff --git a/exercises/D-strings/exercise.js b/exercises/D-strings/exercise.js
index 2cffa6a81..0426f85a6 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,4 @@
 // Start by creating a variable `message`
-
+var message = " This is a greeting";
 console.log(message);
+console.log(typeof message);
diff --git a/exercises/E-strings-concatenation/exercise.js b/exercises/E-strings-concatenation/exercise.js
index 2cffa6a81..51ee7c3cf 100644
--- a/exercises/E-strings-concatenation/exercise.js
+++ b/exercises/E-strings-concatenation/exercise.js
@@ -1,3 +1,4 @@
 // Start by creating a variable `message`
-
-console.log(message);
+var message = "Hello,  Good evening";
+var name = "Senait";
+console.log(message + " " + name);
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..05afb4c13 100644
--- a/exercises/F-strings-methods/exercise.js
+++ b/exercises/F-strings-methods/exercise.js
@@ -1,3 +1,10 @@
 // Start by creating a variable `message`
-
-console.log(message);
+var message = "senait";
+var nameLength;
+console.log(
+  "My name is " +
+    message +
+    " and my name is " +
+    message.length +
+    " characters long."
+);
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..7a3b9a34e 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,4 @@
-const name = " Daniel  ";
+const name = " Daniel ";
+var message = name.length;
 
 console.log(message);
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..1e544e2a2 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 numberOfMentors = 20;
+var numberOfStudents = 38;
+var total = numberOfMentors + numberOfStudents;
+console.log("number of numberOfMentors: " + numberOfMentors);
+console.log("number of students: " + numberOfStudents);
+console.log("Total number of students and mentors is " + total);
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..4cc57df01 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,11 @@
 var numberOfStudents = 15;
 var numberOfMentors = 8;
+var total = numberOfMentors + numberOfStudents;
+var percentageOfStudents = (numberOfStudents / total) * 100;
+var percentageOfMentors = (numberOfMentors / total) * 100;
+console.log("Percentage Students " + percentageOfStudents + "%");
+console.log("percentage Mentors " + percentageOfMentors + "%");
+var roundedPercentageOfStudents = Math.round(percentageOfStudents);
+var roundedPercentageOfMentors = Math.round(percentageOfMentors);
+console.log(roundedPercentageOfMentors + "%");
+console.log(roundedPercentageOfStudents + "%");
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..040d09eec 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,7 +1,10 @@
 function halve(number) {
   // complete the function here
+  return number / 2;
 }
 
 var result = halve(12);
-
 console.log(result);
+console.log(halve(20));
+console.log(halve(76));
+console.log(halve(55));
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..3389638d9 100644
--- a/exercises/J-functions/exercise2.js
+++ b/exercises/J-functions/exercise2.js
@@ -1,7 +1,14 @@
 function triple(number) {
   // complete function here
+  return number * 3;
 }
 
 var result = triple(12);
 
 console.log(result);
+console.log(triple(10));
+console.log(triple(4));
+console.log(triple(32));
+console.log(triple(9));
+console.log(triple(12));
+console.log(triple(42));
diff --git a/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..33545f633 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,9 +1,14 @@
 // Complete the function so that it takes input parameters
-function multiply() {
+function multiply(a, b) {
   // Calculate the result of the function and return it
+  return a * b;
 }
 
 // Assign the result of calling the function the variable `result`
 var result = multiply(3, 4);
 
 console.log(result);
+console.log(multiply(5, 4));
+console.log(multiply(1, 4));
+console.log(multiply(15, 14));
+console.log(multiply(20, 40));
diff --git a/exercises/K-functions-parameters/exercise2.js b/exercises/K-functions-parameters/exercise2.js
index db7a8904b..3b363eecd 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,5 +1,11 @@
 // Declare your function first
-
+function divide(a, b) {
+  return a / b;
+}
 var result = divide(3, 4);
 
 console.log(result);
+console.log(divide(45, 5));
+console.log(divide(34, 6));
+console.log(divide(30, 6));
+console.log(divide(3, 60));
diff --git a/exercises/K-functions-parameters/exercise3.js b/exercises/K-functions-parameters/exercise3.js
index 537e9f4ec..cae5cf1ec 100644
--- a/exercises/K-functions-parameters/exercise3.js
+++ b/exercises/K-functions-parameters/exercise3.js
@@ -1,5 +1,5 @@
 // Write your function here
-
+function createGreeting(name) {
+  console.log("Hello " + 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..3ecd4079d 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,7 @@
 // Declare your function first
-
-// Call the function and assign to a variable `sum`
-
+function sum(a, b) {
+  return a + b;
+}
+// Call the function and assign to a variable `sum
+var sum = sum(13, 124);
 console.log(sum);
diff --git a/exercises/K-functions-parameters/exercise5.js b/exercises/K-functions-parameters/exercise5.js
index 7c5bcd605..0542f6cac 100644
--- a/exercises/K-functions-parameters/exercise5.js
+++ b/exercises/K-functions-parameters/exercise5.js
@@ -1,5 +1,6 @@
 // Declare your function here
-
+function createLongGreeting(name, age) {
+  return "My name is " + "name" + " I am " + age;
+}
 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..34cc26b71 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -3,3 +3,13 @@ var mentor2 = "Irina";
 var mentor3 = "Mimi";
 var mentor4 = "Rob";
 var mentor5 = "Yohannes";
+var name;
+
+function shoutyGreeting(name) {
+  var nameAndGreeting = console.log(("Hello " + name).toUpperCase());
+}
+shoutyGreeting(mentor1);
+shoutyGreeting(mentor2);
+shoutyGreeting(mentor3);
+shoutyGreeting(mentor4);
+shoutyGreeting(mentor5);
diff --git a/extra/1-currency-conversion.js b/extra/1-currency-conversion.js
index 70a2fe863..16efe483d 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(GBP) {
+  return GBP * 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(GBP) {
+  return 0.99 * GBP * 5.7;
+}
 
 /* ======= 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/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index 0a21afd1b..4e8909973 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) {
-    return 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;
 }
 
 /* 
@@ -24,19 +24,25 @@ To run these tests type `node 1-syntax-errors.js` into your terminal
 ===================================================
 */
 
-const util = require('util');
+const util = require("util");
 
 function test(test_name, actual, expected) {
-    let status;
-    if (actual === expected) {
-        status = "PASSED";
-    } else {
-        status = `FAILED: expected: ${util.inspect(expected)} but your function returned: ${util.inspect(actual)}`;
-    }
-
-    console.log(`${test_name}: ${status}`);
+  let status;
+  if (actual === expected) {
+    status = "PASSED";
+  } else {
+    status = `FAILED: expected: ${util.inspect(
+      expected
+    )} but your function returned: ${util.inspect(actual)}`;
+  }
+
+  console.log(`${test_name}: ${status}`);
 }
 
 test("fixed addNumbers function - case 1", addNumbers(3, 4, 6), 13);
-test("fixed introduceMe function", introduceMe("Sonjide", 27), "Hello, my name is Sonjide and I am 27 years old");
+test(
+  "fixed introduceMe function",
+  introduceMe("Sonjide", 27),
+  "Hello, my name is Sonjide and I am 27 years old"
+);
 test("fixed getTotal function", getTotal(23, 5), "The total is 28");
diff --git a/mandatory/2-logic-error.js b/mandatory/2-logic-error.js
index 3c578ad87..1f1245b39 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 getWordLength(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 c9221a200..48eb64d30 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -1,9 +1,11 @@
 // Add comments to explain what this function does. You're meant to use Google!
+//returns pseudo-random number in the range 0 to less than 1 (inclusive of 0, but not 1) and multiply it by 10.
 function getNumber() {
   return Math.random() * 10;
 }
 
 // Add comments to explain what this function does. You're meant to use Google!
+//concatenates strings in in this case w1 and w2
 function s(w1, w2) {
   return w1.concat(w2);
 }
@@ -11,6 +13,7 @@ function s(w1, w2) {
 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 c9e41c691..0423f0dd4 100644
--- a/mandatory/4-tax.js
+++ b/mandatory/4-tax.js
@@ -4,8 +4,12 @@
   A business requires a program that calculates how much sales tax to charge
   Sales tax is 20% of the price of the product
 */
-
-function calculateSalesTax() {}
+var salesMoney;
+var tax;
+function calculateSalesTax(salesMoney, tax) {
+  tax = salesMoney + (salesMoney * 20) / 100;
+  return tax;
+}
 
 /*
   CURRENCY FORMATTING
@@ -17,7 +21,10 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function addTaxAndFormatCurrency() {}
+function addTaxAndFormatCurrency(salesMoney) {
+  const taxedSalesMoney = calculateSalesTax(salesMoney);
+  return "£" + taxedSalesMoney.toFixed(2);
+}
 
 /* 
 ===================================================