diff --git a/1-exercises/A-undefined/exercise.js b/1-exercises/A-undefined/exercise.js
index 0acfc78d..e1a37460 100644
--- a/1-exercises/A-undefined/exercise.js
+++ b/1-exercises/A-undefined/exercise.js
@@ -12,25 +12,37 @@
 // Example 1
 let a;
 console.log(a);
-
+/*Answer
+The code in example 1 will output undefined beasue a value has not been assigned to variable a,
+So, when the program exacutes the code in line 14 will not get any output value.
+*/
 
 // Example 2
 function sayHello() {
-    let message = "Hello";
+  let message = "Hello";
 }
 
 let hello = sayHello();
 console.log(hello);
 
+/*
+The sayHello() function in example 2, is not return any value, therefore the program will print out undefined.
+*/
 
 // Example 3
 function sayHelloToUser(user) {
-    console.log(`Hello ${user}`);
+  console.log(`Hello ${user}`);
 }
 
 sayHelloToUser();
 
+/* Answer for example 3
+The funciton is called with not value, to replace the 'user' parameter
+*/
 
 // Example 4
-let arr = [1,2,3];
+let arr = [1, 2, 3];
 console.log(arr[3]);
+/*
+Index 3 is not defined means there is no value in index 3. Therefore, the program will output undefined message.
+*/
diff --git a/1-exercises/B-while-loop/exercise.js b/1-exercises/B-while-loop/exercise.js
index b459888f..02a7c609 100644
--- a/1-exercises/B-while-loop/exercise.js
+++ b/1-exercises/B-while-loop/exercise.js
@@ -1,12 +1,18 @@
 /*
     while loops can be useful when you want to execute some code as long as some condition is true.    
 
-    Using a while loop, complete the function below so it logs (using console.log) the first n even numbers as a comma-seperated string.
+    Using a while loop, complete the function below so it logs (using console.log) 
+    the first n even numbers as a comma-seperated string.
     The list of numbers should start with 0. n is being passed in as a parameter.
 */
 
 function evenNumbers(n) {
-    // TODO
+  // TODO
+  let i = 0;
+  while (i % 2 === 0) {
+    console.log();
+    i++;
+  }
 }
 
 evenNumbers(3); // should output 0,2,4
diff --git a/1-exercises/C-while-loop-with-array/exercise.js b/1-exercises/C-while-loop-with-array/exercise.js
index d584cd75..7c61f1fe 100644
--- a/1-exercises/C-while-loop-with-array/exercise.js
+++ b/1-exercises/C-while-loop-with-array/exercise.js
@@ -1,7 +1,9 @@
 /*
     Loops can be useful when working with arrays.
-    In the below example, imagine we've defined an array holding the birthdays of your closest friends.
-    Use a while loop to search through the array until you find the first birthday in July, then return that birthday from the function.
+    In the below example, 
+    imagine we've defined an array holding the birthdays of your closest friends.
+    Use a while loop to search through the array until you find the first birthday in July, 
+    then return that birthday from the function.
 */
 
 const BIRTHDAYS = [
@@ -16,8 +18,42 @@ const BIRTHDAYS = [
     "November 15th"
 ];
 
+console.log();
+
 function findFirstJulyBDay(birthdays) {
-    // TODO
+  // TODO
+// lets sort the array first a-z
+  
+  birthdays.sort();
+  let i = 0;
+  while (i < birthdays.length) {
+    if (birthdays[i].includes('July')) {
+      return birthdays[i]
+    }
+    i++
+  }
+  /*
+  using for loop
+
+
+  BIRTHDAYS.sort();
+  for (let i = 0; i < birthdays.length; i++){
+    if (birthdays[i].includes('July')) {
+      return  birthdays[i]
+    }
+
+  }
+  */
 }
 
 console.log(findFirstJulyBDay(BIRTHDAYS)); // should output "July 11th"
+
+/*
+let i = 0;
+    while (birthdays[i] === 'July 11th') {
+        console.log(birthdays[i])
+        i++;
+    }
+    
+    return birthdays[i] = birthdays[i];
+*/
\ No newline at end of file
diff --git a/1-exercises/D-do-while/exercise.js b/1-exercises/D-do-while/exercise.js
index f10d0764..db561bf3 100644
--- a/1-exercises/D-do-while/exercise.js
+++ b/1-exercises/D-do-while/exercise.js
@@ -1,15 +1,44 @@
 /*
-    Sometimes when using loops, we'll want to execute the body of the loop at least once. We can make sure this happens by using a do-while loop.
+    Sometimes when using loops, we'll want to execute the body of the loop at least once. 
+    We can make sure this happens by using a do-while loop.
         - If the condition in a while loop is initially false, the body of the loop will never execute
-        - But in a do-while loop, because the condition is checked after the body, we know that it will always execute at least once
+        - But in a do-while loop, because the condition is checked after the body, 
+          we know that it will always execute at least once
     
-    Using a do-while loop, write a function which returns the sum of the first n even numbers (starting from 0)
+    1 Using a do-while loop, 
+    2 write a function which returns 
+      *the sum of 
+      *the first n even numbers (starting from 0)
 */
 
 function evenNumbersSum(n) {
     // TODO
+   
+    let sum = 0;
+     let arr = [];
+    for (let i = 0; i < n; i++){
+        if (i >0 && i % 2 === 0) {
+            arr.push(i);
+        };
+         for (let j = 0; j < arr; j++) {
+          console.log(arr[j]);
+         }
+    //  console.log(sum)
+    } 
+    // return sum;
 }
+evenNumbersSum(10);
 
-console.log(evenNumbersSum(3)); // should output 6
-console.log(evenNumbersSum(0)); // should output 0
-console.log(evenNumbersSum(10)); // should output 90
\ No newline at end of file
+/*
+  if (n[i] % 2 === 0) {
+            let arr = [];
+            arr.push(n[i]);
+        }
+*/
+//evenNumbersSum(10);
+// console.log(n)
+/* 
+console.log(evenNumbersSum(3));  should output 6
+console.log(evenNumbersSum(0));  should output 0
+ console.log(evenNumbersSum(10)); should output 90
+*/
diff --git a/1-exercises/E-for-loop/exercise1.js b/1-exercises/E-for-loop/exercise1.js
index db5fac64..492726bf 100644
--- a/1-exercises/E-for-loop/exercise1.js
+++ b/1-exercises/E-for-loop/exercise1.js
@@ -4,11 +4,14 @@
     Change the while loop below into a for loop.
 */
 
-
 // Change the below code to use a for loop instead of a while loop.
-let i = 0;
-while(i < 26) {
-    console.log(String.fromCharCode(97 + i));
-    i++;
+// let i = 0;
+// while(i < 26) {
+
+//     i++;
+// }
+
+for (let i = 0; i < 26; i++) {
+  console.log(String.fromCharCode(97 + i));
 }
 // The output shouldn't change.
diff --git a/1-exercises/E-for-loop/exercise2.js b/1-exercises/E-for-loop/exercise2.js
index 081002b2..4ebbb832 100644
--- a/1-exercises/E-for-loop/exercise2.js
+++ b/1-exercises/E-for-loop/exercise2.js
@@ -27,7 +27,9 @@ const AGES = [
 ];
 
 // TODO - Write for loop code here
-
+for (let i = 0; i < WRITERS.length; i++){
+    console.log(`${WRITERS[i]} ${AGES[i]} years old`);
+}
 /*
 The output should look something like this:
 
diff --git a/1-exercises/F-for-of-loop/exercise.js b/1-exercises/F-for-of-loop/exercise.js
index 65585c6a..b3728915 100644
--- a/1-exercises/F-for-of-loop/exercise.js
+++ b/1-exercises/F-for-of-loop/exercise.js
@@ -4,13 +4,20 @@
 
 // TODO Use a for-of loop to output each of the tube stations below.
 let tubeStations = [
-    "Aldgate",
-    "Baker Street",
-    "Picadilly Circus",
-    "Oxford Street",
-    "Tottenham Court Road"
+  "Aldgate",
+  "Baker Street",
+  "Picadilly Circus",
+  "Oxford Street",
+  "Tottenham Court Road",
 ];
 
+for (let x of tubeStations) {
+  console.log(x);
+}
+
 
 // TODO Use a for-of loop to capitalise and output each letter in the string seperately.
 let str = "codeyourfuture";
+for (let i of str) {
+  console.log(i.toUpperCase());
+}
diff --git a/2-mandatory/1-weather-report.js b/2-mandatory/1-weather-report.js
index dcc2bdb0..bb7c0ce1 100644
--- a/2-mandatory/1-weather-report.js
+++ b/2-mandatory/1-weather-report.js
@@ -12,9 +12,29 @@
 */
 
 function getTemperatureReport(cities) {
-    // TODO
+  // TODO
+  return cities.map(city => `The temperature in ${city} is ${temperatureService(city)} degrees`)
+
 }
 
+// console.log(getTemperatureReport(["London", "Paris", "São Paulo"]));
+  
+/*
+   for (let city of cities) {
+    return `The temperature in ${temperatureService(city)} degrees`
+  }
+cities.forEach((element, i) => {
+  console.log(element, i)
+});
+  */
+/*
+getTemperatureReport([
+"London",
+"Paris",
+"São Paulo"
+])
+ */
+
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 
@@ -31,6 +51,7 @@ function temperatureService(city) {
     
     return temparatureMap.get(city);
 }
+// getTemperatureReport(cities);
 
 test("should return a temperature report for the user's cities", () => {
     let usersCities = [
diff --git a/2-mandatory/2-retrying-random-numbers.js b/2-mandatory/2-retrying-random-numbers.js
index 10aab37d..3ec34525 100644
--- a/2-mandatory/2-retrying-random-numbers.js
+++ b/2-mandatory/2-retrying-random-numbers.js
@@ -6,13 +6,22 @@
 // This function shouldn't be changed
 function generateRandomNumber() {
     console.log("Generating number...");
-    return Math.round(Math.random() * 100);
+    return Math.round(Math.random() * 100) ;
 }
 
 function getRandomNumberGreaterThan50() {
     // TODO - implement using a do-while loop
+ 
+let i = 0;
+do {
+     i = generateRandomNumber();
+    
+    } while (i < 50);
+
+    return i;
 }
 
+
 /* ======= TESTS - DO NOT MODIFY ===== */
 
 test("Returned value should always be greater than 50", () => {
diff --git a/2-mandatory/3-financial-times.js b/2-mandatory/3-financial-times.js
index 2ce6fb73..0ec446f9 100644
--- a/2-mandatory/3-financial-times.js
+++ b/2-mandatory/3-financial-times.js
@@ -4,8 +4,24 @@
     The home page of the web site has a headline section, which only has space for article titles which are 65 characters or less.
     Implement the function below, which will return a new array containing only article titles which will fit.
 */
+
 function potentialHeadlines(allArticleTitles) {
-    // TODO
+  // TODO
+  // using filter method
+
+  return allArticleTitles.filter((article) => article.length <= 65);
+
+  /*
+     let pritableArticles = [];
+    for (let i = 0; i < allArticleTitles.length; i++) {
+        if (allArticleTitles[i].length < 66) {
+        pritableArticles.push(allArticleTitles[i]);
+    }
+  }
+
+    return pritableArticles;
+    
+    */
 }
 
 /*
@@ -14,7 +30,30 @@ function potentialHeadlines(allArticleTitles) {
     (you can assume words will always be seperated by a space)
 */
 function titleWithFewestWords(allArticleTitles) {
-    // TODO
+  // TODO
+
+  const wordCount = allArticleTitles.map(
+    (article) => article.split(" ").length
+  );
+
+  const theSmallest = Math.min(...wordCount);
+
+  return allArticleTitles[wordCount.indexOf(theSmallest)];
+
+  /*
+for (let i = 0; i < allArticleTitles.length; i++) {
+        console.log(allArticleTitles[i].split(" ").length);
+    }
+
+*/
+  /*
+let myArr = [];
+ for (let i = 0; i < allArticleTitles.length; i++) {
+     myArr.push(allArticleTitles[i].split(" ").length); 
+    } 
+    let leastWords = Math.min(...myArr);
+   return leastWords; 
+*/
 }
 
 /*
@@ -23,7 +62,10 @@ function titleWithFewestWords(allArticleTitles) {
     (Hint: remember that you can also loop through the characters of a string if you need to)
 */
 function headlinesWithNumbers(allArticleTitles) {
-    // TODO
+  // TODO
+    
+    return allArticleTitles.filter(article => /\d/.test(article));
+    
 }
 
 /*
@@ -31,24 +73,33 @@ function headlinesWithNumbers(allArticleTitles) {
     Implement the function below to return this number - rounded to the nearest integer.
 */
 function averageNumberOfCharacters(allArticleTitles) {
-    // TODO
+  // TODO
+    let totalCharacters = 0;
+    for (let i = 0; i < allArticleTitles.length; i++) {
+        totalCharacters += allArticleTitles[i].length;
+    }
+    
+    return Math.floor(Math.round(totalCharacters / allArticleTitles.length));
 }
 
-
-
 /* ======= List of Articles - DO NOT MODIFY ===== */
 const ARTICLE_TITLES = [
-    "Streaming wars drive media groups to spend more than $100bn on new content",
-    "Amazon Prime Video India country head: streaming is driving a TV revolution",
-    "Aerospace chiefs prepare for bumpy ride in recovery of long-haul flights",
-    "British companies look to muscle in on US retail investing boom",
-    "Libor to take firm step towards oblivion on New Year's Day",
-    "Audit profession unattractive to new recruits, says PwC boss",
-    "Chinese social media users blast Elon Musk over near miss in space",
-    "Companies raise over $12tn in 'blockbuster' year for global capital markets",
-    "The three questions that dominate investment",
-    "Brussels urges Chile's incoming president to endorse EU trade deal",
+  "Streaming wars drive media groups to spend more than $100bn on new content",
+  "Amazon Prime Video India country head: streaming is driving a TV revolution",
+  "Aerospace chiefs prepare for bumpy ride in recovery of long-haul flights",
+  "British companies look to muscle in on US retail investing boom",
+  "Libor to take firm step towards oblivion on New Year's Day",
+  "Audit profession unattractive to new recruits, says PwC boss",
+  "Chinese social media users blast Elon Musk over near miss in space",
+  "Companies raise over $12tn in 'blockbuster' year for global capital markets",
+  "The three questions that dominate investment",
+  "Brussels urges Chile's incoming president to endorse EU trade deal",
 ];
+// console.log(averageNumberOfCharacters(ARTICLE_TITLES));
+// console.log(headlinesWithNumbers(ARTICLE_TITLES),"-----------");
+// console.log(titleWithFewestWords(ARTICLE_TITLES));
+// // console.log(headlinesWithNumbers(ARTICLE_TITLES));
+// console.log(potentialHeadlines(ARTICLE_TITLES), "using filter method");
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 
@@ -79,3 +130,4 @@ test("should only return headlines containing numbers", () => {
 test("should return the average number of characters in a headline", () => {
     expect(averageNumberOfCharacters(ARTICLE_TITLES)).toEqual(65);
 });
+
diff --git a/2-mandatory/4-stocks.js b/2-mandatory/4-stocks.js
index 72d62f94..037210a9 100644
--- a/2-mandatory/4-stocks.js
+++ b/2-mandatory/4-stocks.js
@@ -18,6 +18,16 @@ const CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS = [
     [1101.30, 1093.94, 1067.00, 1008.87, 938.53] // TSLA
 ];
 
+/*
+let total = 0;
+    for (let i = 0; i < CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS.length; i++) {
+      total += CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS[i];
+      return total;
+    }
+console.log(total);
+*/
+
+
 /*
     We want to understand what the average price over the last 5 days for each stock is.
     Implement the below function, which
@@ -35,8 +45,26 @@ const CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS = [
 */
 function getAveragePrices(closingPricesForAllStocks) {
     // TODO
+    let arr = [];
+    let total = 0;
+        closingPricesForAllStocks.forEach((element, i) => {
+            // console.log(element, element[i]);
+            total += element[i];
+            
+            arr.push(total)
+        });
+   
+    return arr;
+
 }
 
+
+
+    /*
+    1) create for loop to go throught the outer array
+    2) create inter for loop to go throught each element in the outer array
+    */
+
 /*
     We also want to see what the change in price is from the first day to the last day for each stock.
     Implement the below function, which
diff --git a/3-extra/1-factorial.js b/3-extra/1-factorial.js
index 31f8052c..dd1540b7 100644
--- a/3-extra/1-factorial.js
+++ b/3-extra/1-factorial.js
@@ -9,9 +9,19 @@
 */
 
 function factorial(input) {
-    // TODO
+  // Create new array to collect numbers
+  let arrayOfFactorial = [];
+    for (let i = 1; i < input + 1; i++){
+    arrayOfFactorial.push(i)
+    }
+// Used reduce method to multiply elements each other
+  const product = arrayOfFactorial.reduce((prevousValue, currentValue) => prevousValue * currentValue)
+
+    return product;
 }
 
+
+
 /* ======= TESTS - DO NOT MODIFY ===== */
 
 test("3! should be 6", () => {