diff --git a/1-exercises/A-undefined/exercise.js b/1-exercises/A-undefined/exercise.js
index 0acfc78d..6ffd204d 100644
--- a/1-exercises/A-undefined/exercise.js
+++ b/1-exercises/A-undefined/exercise.js
@@ -12,25 +12,26 @@
 // Example 1
 let a;
 console.log(a);
-
+//this is because a has not been assigned a value.
 
 // Example 2
 function sayHello() {
-    let message = "Hello";
+  let message = "Hello";
 }
 
 let hello = sayHello();
 console.log(hello);
-
+//nothing is being returned from the function therefore the variable "hello" contains nothing and is undefined.
 
 // Example 3
 function sayHelloToUser(user) {
-    console.log(`Hello ${user}`);
+  console.log(`Hello ${user}`);
 }
 
 sayHelloToUser();
-
+//no user argument was passed on as a parameter therefore calling it in the function will be undefined.
 
 // Example 4
-let arr = [1,2,3];
+let arr = [1, 2, 3];
 console.log(arr[3]);
+//there is no value at arr[3] which is the fourth position.
diff --git a/1-exercises/B-while-loop/exercise.js b/1-exercises/B-while-loop/exercise.js
index b459888f..dda723b6 100644
--- a/1-exercises/B-while-loop/exercise.js
+++ b/1-exercises/B-while-loop/exercise.js
@@ -3,10 +3,30 @@
 
     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.
+
+    0,2,4,6,8,10,12,14,16,18,20 - even numbers
+    1,3,5,7,9,11,13,15 - odd numbers
+    evenNumbers(3); 
+
 */
 
+//PSEUDO CODE - display even numbers starting at a 0 and ending the n amount of Times passed in.
+// evenNumbers(3); // should output 0,2,4
+// evenNumbers(0); // should output nothing
+// evenNumbers(4); // should output 0,2,4,6
+
 function evenNumbers(n) {
-    // TODO
+  // TODO
+
+  let i = 0;
+  let evenArr = [];
+
+  while (i < n) {
+    //increment i
+    evenArr.push(i * 2);
+    i++;
+  }
+  console.log(evenArr.join(", "));
 }
 
 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..c17785a0 100644
--- a/1-exercises/C-while-loop-with-array/exercise.js
+++ b/1-exercises/C-while-loop-with-array/exercise.js
@@ -5,19 +5,32 @@
 */
 
 const BIRTHDAYS = [
-    "January 7th",
-    "February 12th",
-    "April 3rd",
-    "April 5th",
-    "May 3rd",
-    "July 11th",
-    "July 17th",
-    "September 28th",
-    "November 15th"
+  "January 7th",
+  "February 12th",
+  "April 3rd",
+  "April 5th",
+  "May 3rd",
+  "July 11th",
+  "July 17th",
+  "September 28th",
+  "November 15th",
 ];
 
 function findFirstJulyBDay(birthdays) {
-    // TODO
+  let i = 0;
+  let bdayCheck;
+
+  while (i < birthdays.length - 1) {
+    bdayCheck = birthdays[i];
+
+    if (bdayCheck.startsWith("July")) {
+      return bdayCheck;
+    }
+
+    i++;
+  }
+
+  // TODO
 }
 
 console.log(findFirstJulyBDay(BIRTHDAYS)); // should output "July 11th"
diff --git a/1-exercises/D-do-while/exercise.js b/1-exercises/D-do-while/exercise.js
index f10d0764..64a978b6 100644
--- a/1-exercises/D-do-while/exercise.js
+++ b/1-exercises/D-do-while/exercise.js
@@ -4,12 +4,23 @@
         - 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)
+    //0,2,4,6,8 - even numbers
 */
 
 function evenNumbersSum(n) {
-    // TODO
+  // TODO
+
+  let i = 0;
+  //initialise sum to 0 so that the variable is a number
+  let sum = 0;
+
+  do {
+    sum = sum + i * 2;
+    i++;
+  } while (i < n);
+  return sum;
 }
 
 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
+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..9e22e69f 100644
--- a/1-exercises/E-for-loop/exercise1.js
+++ b/1-exercises/E-for-loop/exercise1.js
@@ -4,11 +4,9 @@
     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++;
+
+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..9d6148fa 100644
--- a/1-exercises/E-for-loop/exercise2.js
+++ b/1-exercises/E-for-loop/exercise2.js
@@ -11,23 +11,23 @@
 */
 
 const WRITERS = [
-    "Virginia Woolf",
-    "Zadie Smith",
-    "Jane Austen",
-    "Bell Hooks",
-    "Yukiko Motoya"
-]
-
-const AGES = [
-    59,
-    40,
-    41,
-    63,
-    49
+  "Virginia Woolf",
+  "Zadie Smith",
+  "Jane Austen",
+  "Bell Hooks",
+  "Yukiko Motoya",
 ];
 
+const AGES = [59, 40, 41, 63, 49];
+
 // TODO - Write for loop code here
 
+//Virginia Woolf is 59 years old
+
+for (let i = 0; i < WRITERS.length; i++) {
+  console.log(`${WRITERS[i]} is ${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..051e19e7 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 station of tubeStations) {
+  console.log(station);
+}
 
 // TODO Use a for-of loop to capitalise and output each letter in the string seperately.
 let str = "codeyourfuture";
+
+for (let letter of str) {
+  console.log(letter.toUpperCase());
+}
diff --git a/2-mandatory/1-weather-report.js b/2-mandatory/1-weather-report.js
index dcc2bdb0..b94dc992 100644
--- a/2-mandatory/1-weather-report.js
+++ b/2-mandatory/1-weather-report.js
@@ -6,58 +6,60 @@
 
     Implement the function below:
         - take the array of cities as a parameter
-        - return an array of strings, which is a statement about the temperature of each city.
+        - return an array of strings, which is a statement about the temperature of each city.  return
             For example, "The temperature in London is 10 degrees"
         - Hint: you can call the temperatureService function from your function
 */
 
 function getTemperatureReport(cities) {
-    // TODO
-}
+  // TODO
+ 
+  let tempArray = [];
+
+  for (let city of cities) {
+    tempArray.push(
+      `The temperature in ${city} is ${temperatureService(city)} degrees`
+    );
+  }
 
+  return tempArray;
+}
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 
 function temperatureService(city) {
-    let temparatureMap  = new Map();
-
-    temparatureMap.set('London', 10);
-    temparatureMap.set('Paris', 12);
-    temparatureMap.set('Barcelona', 17);
-    temparatureMap.set('Dubai', 27);
-    temparatureMap.set('Mumbai', 29);
-    temparatureMap.set('São Paulo', 23);
-    temparatureMap.set('Lagos', 33);
-    
-    return temparatureMap.get(city);
+  let temparatureMap = new Map();
+
+  temparatureMap.set("London", 10);
+  temparatureMap.set("Paris", 12);
+  temparatureMap.set("Barcelona", 17);
+  temparatureMap.set("Dubai", 27);
+  temparatureMap.set("Mumbai", 29);
+  temparatureMap.set("São Paulo", 23);
+  temparatureMap.set("Lagos", 33);
+
+  return temparatureMap.get(city);
 }
 
 test("should return a temperature report for the user's cities", () => {
-    let usersCities = [
-        "London",
-        "Paris",
-        "São Paulo"
-    ]
-
-    expect(getTemperatureReport(usersCities)).toEqual([
-        "The temperature in London is 10 degrees",
-        "The temperature in Paris is 12 degrees",
-        "The temperature in São Paulo is 23 degrees"
-    ]);
+  let usersCities = ["London", "Paris", "São Paulo"];
+
+  expect(getTemperatureReport(usersCities)).toEqual([
+    "The temperature in London is 10 degrees",
+    "The temperature in Paris is 12 degrees",
+    "The temperature in São Paulo is 23 degrees",
+  ]);
 });
 
 test("should return a temperature report for the user's cities (alternate input)", () => {
-    let usersCities = [
-        "Barcelona",
-        "Dubai"
-    ]
-
-    expect(getTemperatureReport(usersCities)).toEqual([
-        "The temperature in Barcelona is 17 degrees",
-        "The temperature in Dubai is 27 degrees"
-    ]);
+  let usersCities = ["Barcelona", "Dubai"];
+
+  expect(getTemperatureReport(usersCities)).toEqual([
+    "The temperature in Barcelona is 17 degrees",
+    "The temperature in Dubai is 27 degrees",
+  ]);
 });
 
 test("should return an empty array if the user hasn't selected any cities", () => {
-    expect(getTemperatureReport([])).toEqual([]);
-});
\ No newline at end of file
+  expect(getTemperatureReport([])).toEqual([]);
+});
diff --git a/2-mandatory/2-retrying-random-numbers.js b/2-mandatory/2-retrying-random-numbers.js
index 10aab37d..dc5b1d4d 100644
--- a/2-mandatory/2-retrying-random-numbers.js
+++ b/2-mandatory/2-retrying-random-numbers.js
@@ -5,20 +5,25 @@
 
 // This function shouldn't be changed
 function generateRandomNumber() {
-    console.log("Generating number...");
-    return Math.round(Math.random() * 100);
+  console.log("Generating number...");
+  return Math.round(Math.random() * 100);
 }
 
 function getRandomNumberGreaterThan50() {
-    // TODO - implement using a do-while loop
+  // TODO - implement using a do-while loop
+  let num = 0;
+  do {
+    num = generateRandomNumber();
+  } while (num <= 50);
+  return num;
 }
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 
 test("Returned value should always be greater than 50", () => {
-    expect(getRandomNumberGreaterThan50()).toBeGreaterThan(50);
-    expect(getRandomNumberGreaterThan50()).toBeGreaterThan(50);
-    expect(getRandomNumberGreaterThan50()).toBeGreaterThan(50);
-    expect(getRandomNumberGreaterThan50()).toBeGreaterThan(50);
-    expect(getRandomNumberGreaterThan50()).toBeGreaterThan(50);
+  expect(getRandomNumberGreaterThan50()).toBeGreaterThan(50);
+  expect(getRandomNumberGreaterThan50()).toBeGreaterThan(50);
+  expect(getRandomNumberGreaterThan50()).toBeGreaterThan(50);
+  expect(getRandomNumberGreaterThan50()).toBeGreaterThan(50);
+  expect(getRandomNumberGreaterThan50()).toBeGreaterThan(50);
 });
diff --git a/2-mandatory/3-financial-times.js b/2-mandatory/3-financial-times.js
index 2ce6fb73..12bdf603 100644
--- a/2-mandatory/3-financial-times.js
+++ b/2-mandatory/3-financial-times.js
@@ -5,7 +5,19 @@
     Implement the function below, which will return a new array containing only article titles which will fit.
 */
 function potentialHeadlines(allArticleTitles) {
-    // TODO
+  // TODO
+  //loop through allArticleTitles - for of loop
+  //find all titles <= 65 characters - .length
+  //return new array with titles that fit - return ; new array
+
+  let fittingTitles = [];
+
+  for (let title of allArticleTitles) {
+    if (title.length <= 65) {
+      fittingTitles.push(title);
+    }
+  }
+  return fittingTitles;
 }
 
 /*
@@ -14,7 +26,19 @@ function potentialHeadlines(allArticleTitles) {
     (you can assume words will always be seperated by a space)
 */
 function titleWithFewestWords(allArticleTitles) {
-    // TODO
+  // TODO
+  let fewestWords = allArticleTitles[0];
+  let prevWords = allArticleTitles[0].split(" ").length;
+
+  for (let i = 1; i < allArticleTitles.length; i++) {
+    let wordArray = allArticleTitles[i].split(" ").length;
+    if (wordArray < prevWords) {
+      fewestWords = allArticleTitles[i];
+      //   console.log("This is less", allArticleTitles[i]);
+    }
+    prevWords = wordArray;
+  }
+  return fewestWords;
 }
 
 /*
@@ -23,7 +47,23 @@ 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
+  let numberHeadlines = [];
+
+  for (let i = 0; i < allArticleTitles.length; i++) {
+    let checkedTitle = allArticleTitles[i];
+
+    for (let j = 0; j < checkedTitle.length; j++) {
+      let checkNo = Number(checkedTitle[j]);
+
+      if (Number.isInteger(checkNo) && checkNo > 0) {
+        numberHeadlines.push(checkedTitle);
+        break;
+      }
+    }
+  }
+
+  return numberHeadlines;
 }
 
 /*
@@ -31,51 +71,64 @@ function headlinesWithNumbers(allArticleTitles) {
     Implement the function below to return this number - rounded to the nearest integer.
 */
 function averageNumberOfCharacters(allArticleTitles) {
-    // TODO
-}
+  // TODO
+  let sumChars = 0;
 
+  for (let i = 0; i < allArticleTitles.length; i++) {
+    sumChars += allArticleTitles[i].length;
+  }
 
+  let averageChars = sumChars / allArticleTitles.length;
+
+  return Math.round(averageChars);
+}
 
 /* ======= 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",
 ];
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 
 test("should only return potential headlines", () => {
-    expect(new Set(potentialHeadlines(ARTICLE_TITLES))).toEqual(new Set([
-        "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",
-        "The three questions that dominate investment"
-    ]));
+  expect(new Set(potentialHeadlines(ARTICLE_TITLES))).toEqual(
+    new Set([
+      "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",
+      "The three questions that dominate investment",
+    ])
+  );
 });
 
 test("should return an empty array for empty input", () => {
-    expect(potentialHeadlines([])).toEqual([]);
+  expect(potentialHeadlines([])).toEqual([]);
 });
 
 test("should return the title with the fewest words", () => {
-    expect(titleWithFewestWords(ARTICLE_TITLES)).toEqual("The three questions that dominate investment");
+  expect(titleWithFewestWords(ARTICLE_TITLES)).toEqual(
+    "The three questions that dominate investment"
+  );
 });
 
 test("should only return headlines containing numbers", () => {
-    expect(new Set(headlinesWithNumbers(ARTICLE_TITLES))).toEqual(new Set([
-        "Streaming wars drive media groups to spend more than $100bn on new content",
-        "Companies raise over $12tn in 'blockbuster' year for global capital markets"
-    ]));
+  expect(new Set(headlinesWithNumbers(ARTICLE_TITLES))).toEqual(
+    new Set([
+      "Streaming wars drive media groups to spend more than $100bn on new content",
+      "Companies raise over $12tn in 'blockbuster' year for global capital markets",
+    ])
+  );
 });
 
 test("should return the average number of characters in a headline", () => {
-    expect(averageNumberOfCharacters(ARTICLE_TITLES)).toEqual(65);
+  expect(averageNumberOfCharacters(ARTICLE_TITLES)).toEqual(65);
 });
diff --git a/2-mandatory/4-stocks.js b/2-mandatory/4-stocks.js
index 72d62f94..a159f332 100644
--- a/2-mandatory/4-stocks.js
+++ b/2-mandatory/4-stocks.js
@@ -11,11 +11,11 @@
 const STOCKS = ["aapl", "msft", "amzn", "googl", "tsla"];
 
 const CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS = [
-    [179.19, 180.33, 176.28, 175.64, 172.99], // AAPL
-    [340.69, 342.45, 334.69, 333.20, 327.29], // MSFT
-    [3384.44, 3393.39, 3421.37, 3420.74, 3408.34], // AMZN
-    [2951.88, 2958.13, 2938.33, 2928.30, 2869.45], // GOOGL
-    [1101.30, 1093.94, 1067.00, 1008.87, 938.53] // TSLA
+  [179.19, 180.33, 176.28, 175.64, 172.99], // AAPL
+  [340.69, 342.45, 334.69, 333.2, 327.29], // MSFT
+  [3384.44, 3393.39, 3421.37, 3420.74, 3408.34], // AMZN
+  [2951.88, 2958.13, 2938.33, 2928.3, 2869.45], // GOOGL
+  [1101.3, 1093.94, 1067.0, 1008.87, 938.53], // TSLA
 ];
 
 /*
@@ -34,7 +34,20 @@ const CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS = [
         Functions can help with this!
 */
 function getAveragePrices(closingPricesForAllStocks) {
-    // TODO
+  // TODO
+  let averagesArray = [];
+  for (let i = 0; i < closingPricesForAllStocks.length; i++) {
+    let stocksSum = 0;
+    let avgSum = 0;
+    for (let j = 0; j < closingPricesForAllStocks[i].length; j++) {
+      stocksSum += closingPricesForAllStocks[i][j];
+    }
+    avgSum = stocksSum / closingPricesForAllStocks[i].length;
+    let finalNum = avgSum.toFixed(2);
+    averagesArray.push(parseFloat(finalNum));
+  }
+
+  return averagesArray;
 }
 
 /*
@@ -48,7 +61,19 @@ function getAveragePrices(closingPricesForAllStocks) {
     The price change value should be rounded to 2 decimal places, and should be a number (not a string)
 */
 function getPriceChanges(closingPricesForAllStocks) {
-    // TODO
+  // TODO
+
+  let differenceArray = [];
+
+  for (let i = 0; i < closingPricesForAllStocks.length; i++) {
+    let tot = closingPricesForAllStocks[i].length - 1;
+    let diffSum =
+      closingPricesForAllStocks[i][tot] - closingPricesForAllStocks[i][0];
+
+    differenceArray.push(parseFloat(diffSum.toFixed(2)));
+  }
+
+  return differenceArray;
 }
 
 /*
@@ -64,31 +89,47 @@ function getPriceChanges(closingPricesForAllStocks) {
     The price should be shown with exactly 2 decimal places.
 */
 function highestPriceDescriptions(closingPricesForAllStocks, stocks) {
-    // TODO
-}
+  // TODO
+  let highStockPrices = [];
 
+  for (let i = 0; i < closingPricesForAllStocks.length; i++) {
+    let highestTot = 0;
+    for (let j = 0; j < closingPricesForAllStocks[i].length; j++) {
+      if (closingPricesForAllStocks[i][j] > highestTot) {
+        highestTot = closingPricesForAllStocks[i][j];
+      }
+    }
+    highStockPrices.push(
+      `The highest price of ${stocks[
+        i
+      ].toUpperCase()} in the last 5 days was ${highestTot.toFixed(2)}`
+    );
+  }
+
+  return highStockPrices;
+}
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 test("should return the average price for each stock", () => {
-    expect(getAveragePrices(CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS)).toEqual(
-        [176.89, 335.66, 3405.66, 2929.22, 1041.93]
-    );
+  expect(getAveragePrices(CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS)).toEqual([
+    176.89, 335.66, 3405.66, 2929.22, 1041.93,
+  ]);
 });
 
 test("should return the price change for each stock", () => {
-    expect(getPriceChanges(CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS)).toEqual(
-        [-6.2, -13.4, 23.9, -82.43, -162.77]
-    );
+  expect(getPriceChanges(CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS)).toEqual([
+    -6.2, -13.4, 23.9, -82.43, -162.77,
+  ]);
 });
 
 test("should return a description of the highest price for each stock", () => {
-    expect(highestPriceDescriptions(CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS, STOCKS)).toEqual(
-        [
-            "The highest price of AAPL in the last 5 days was 180.33",
-            "The highest price of MSFT in the last 5 days was 342.45",
-            "The highest price of AMZN in the last 5 days was 3421.37",
-            "The highest price of GOOGL in the last 5 days was 2958.13",
-            "The highest price of TSLA in the last 5 days was 1101.30"
-        ]
-    );
+  expect(
+    highestPriceDescriptions(CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS, STOCKS)
+  ).toEqual([
+    "The highest price of AAPL in the last 5 days was 180.33",
+    "The highest price of MSFT in the last 5 days was 342.45",
+    "The highest price of AMZN in the last 5 days was 3421.37",
+    "The highest price of GOOGL in the last 5 days was 2958.13",
+    "The highest price of TSLA in the last 5 days was 1101.30",
+  ]);
 });
diff --git a/3-extra/1-factorial.js b/3-extra/1-factorial.js
index 31f8052c..2df4240e 100644
--- a/3-extra/1-factorial.js
+++ b/3-extra/1-factorial.js
@@ -9,19 +9,26 @@
 */
 
 function factorial(input) {
-    // TODO
+  // TODO
+
+  let calculation = input;
+
+  for (let i = input - 1; i >= 1; i--) {
+    calculation = calculation * i;
+  }
+  return calculation;
 }
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 
 test("3! should be 6", () => {
-    expect(factorial(3)).toEqual(6);
+  expect(factorial(3)).toEqual(6);
 });
 
 test("5! should be 120", () => {
-    expect(factorial(5)).toEqual(120);
+  expect(factorial(5)).toEqual(120);
 });
 
 test("10! should be 3628800", () => {
-    expect(factorial(10)).toEqual(3628800);
+  expect(factorial(10)).toEqual(3628800);
 });
diff --git a/3-extra/2-array-of-objects.js b/3-extra/2-array-of-objects.js
index ee57960f..0565daa7 100644
--- a/3-extra/2-array-of-objects.js
+++ b/3-extra/2-array-of-objects.js
@@ -11,72 +11,103 @@
 */
 
 function getHighestRatedInEachGenre(books) {
-    // TODO
-}
+  let genresArr = [];
+  let highestRating = "";
+  let highestTitle = "";
+
+  function createGenreArray(books) {
+    books.forEach((book) => {
+      if (!genresArr.includes(book.genre)) genresArr.push(book.genre);
+    });
+    return genresArr;
+  }
+
+  function getGenreBooks(genre) {
+    let genreBooksArray = books.filter((book) => book.genre === genre);
+    return genreBooksArray;
+  }
 
+  function highestGenre(genrebook) {
+    highestRating = "";
+    highestTitle = "";
+    genrebook.forEach((book) => {
+      if (book.rating > highestRating) {
+        highestRating = book.rating;
+        highestTitle = book.title;
+      }
+    });
+    return highestTitle;
+  }
+
+  let highestTitlesArr = createGenreArray(books).map((genre) => {
+    let genbooks = getGenreBooks(genre);
+    return highestGenre(genbooks);
+  });
+  return highestTitlesArr; //highestTitles array;
+}
 
 /* ======= Book data - DO NOT MODIFY ===== */
 const BOOKS = [
-    {
-        title: "The Lion, the Witch and the Wardrobe",
-        genre: "children",
-        rating: 4.7
-    },
-    {
-        title: "Sapiens: A Brief History of Humankind",
-        genre: "non-fiction",
-        rating: 4.7
-    },
-    {
-        title: "Nadiya's Fast Flavours",
-        genre: "cooking",
-        rating: 4.7
-    },
-    {
-        title: "Harry Potter and the Philosopher's Stone",
-        genre: "children",
-        rating: 4.8
-    },
-    {
-        title: "A Life on Our Planet",
-        genre: "non-fiction",
-        rating: 4.8
-    },
-    {
-        title: "Dishoom: The first ever cookbook from the much-loved Indian restaurant",
-        genre: "cooking",
-        rating: 4.85
-    },
-    {
-        title: "Gangsta Granny Strikes Again!",
-        genre: "children",
-        rating: 4.9
-    },
-    {
-        title: "Diary of a Wimpy Kid",
-        genre: "children",
-        rating: 4.6
-    },
-    {
-        title: "BOSH!: Simple recipes. Unbelievable results. All plants.",
-        genre: "cooking",
-        rating: 4.6
-    },
-    {
-        title: "The Book Your Dog Wishes You Would Read",
-        genre: "non-fiction",
-        rating: 4.85
-    },
-]
-
+  {
+    title: "The Lion, the Witch and the Wardrobe",
+    genre: "children",
+    rating: 4.7,
+  },
+  {
+    title: "Sapiens: A Brief History of Humankind",
+    genre: "non-fiction",
+    rating: 4.7,
+  },
+  {
+    title: "Nadiya's Fast Flavours",
+    genre: "cooking",
+    rating: 4.7,
+  },
+  {
+    title: "Harry Potter and the Philosopher's Stone",
+    genre: "children",
+    rating: 4.8,
+  },
+  {
+    title: "A Life on Our Planet",
+    genre: "non-fiction",
+    rating: 4.8,
+  },
+  {
+    title:
+      "Dishoom: The first ever cookbook from the much-loved Indian restaurant",
+    genre: "cooking",
+    rating: 4.85,
+  },
+  {
+    title: "Gangsta Granny Strikes Again!",
+    genre: "children",
+    rating: 4.9,
+  },
+  {
+    title: "Diary of a Wimpy Kid",
+    genre: "children",
+    rating: 4.6,
+  },
+  {
+    title: "BOSH!: Simple recipes. Unbelievable results. All plants.",
+    genre: "cooking",
+    rating: 4.6,
+  },
+  {
+    title: "The Book Your Dog Wishes You Would Read",
+    genre: "non-fiction",
+    rating: 4.85,
+  },
+];
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 test("should return the highest rated book in each genre", () => {
-    expect(new Set(getHighestRatedInEachGenre(BOOKS))).toEqual(new Set(
-        [
-            "The Book Your Dog Wishes You Would Read",
-            "Gangsta Granny Strikes Again!",
-            "Dishoom: The first ever cookbook from the much-loved Indian restaurant"
-        ]
-    ));
-});
\ No newline at end of file
+  expect(new Set(getHighestRatedInEachGenre(BOOKS))).toEqual(
+    new Set([
+      "The Book Your Dog Wishes You Would Read",
+      "Gangsta Granny Strikes Again!",
+      "Dishoom: The first ever cookbook from the much-loved Indian restaurant",
+    ])
+  );
+});
diff --git a/3-extra/3-fibonacci.js b/3-extra/3-fibonacci.js
index 9ef9aec7..ea510d8e 100644
--- a/3-extra/3-fibonacci.js
+++ b/3-extra/3-fibonacci.js
@@ -14,24 +14,34 @@
 */
 
 function generateFibonacciSequence(n) {
-    // TODO
+  // TODO
+  let fibonacciArr = [];
+
+  for (i = 0; i < n; i++) {
+    if (i === 0) {
+      fibonacciArr.push(i);
+    } else if (i === 1) {
+      fibonacciArr.push(i);
+    } else {
+      fibonacciArr.push(fibonacciArr[i - 1] + fibonacciArr[i - 2]);
+    }
+  }
+  return fibonacciArr;
 }
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 test("should return the first 10 numbers in the Fibonacci Sequence", () => {
-    expect(generateFibonacciSequence(10)).toEqual(
-        [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
-    );
+  expect(generateFibonacciSequence(10)).toEqual([
+    0, 1, 1, 2, 3, 5, 8, 13, 21, 34,
+  ]);
 });
 
 test("should return the first 5 numbers in the Fibonacci Sequence", () => {
-    expect(generateFibonacciSequence(5)).toEqual(
-        [0, 1, 1, 2, 3]
-    );
+  expect(generateFibonacciSequence(5)).toEqual([0, 1, 1, 2, 3]);
 });
 
 test("should return the first 15 numbers in the Fibonacci Sequence", () => {
-    expect(generateFibonacciSequence(15)).toEqual(
-        [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377]
-    );
-});
\ No newline at end of file
+  expect(generateFibonacciSequence(15)).toEqual([
+    0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377,
+  ]);
+});