diff --git a/src/functions-and-arrays.js b/src/functions-and-arrays.js
index 3a7dbec41..88a2505b8 100644
--- a/src/functions-and-arrays.js
+++ b/src/functions-and-arrays.js
@@ -1,41 +1,91 @@
 // Iteration #1: Find the maximum
-function maxOfTwoNumbers() {}
-
+function maxOfTwoNumbers(num1, num2) {
+  if (num1 > num2) {
+    return num1;
+  }
+  return num2;
+}
+console.log(maxOfTwoNumbers(4, 8));
 
 
 // Iteration #2: Find longest word
 const words = ['mystery', 'brother', 'aviator', 'crocodile', 'pearl', 'orchard', 'crackpot'];
 
-function findLongestWord() {}
-
+function findLongestWord(array) {
+  longestWord = "";
+  if (!array.length) return null;
+  for (const word of array) {
+    if (word.length > longestWord.length) {
+      longestWord = word;
+    }
+  }
+  return longestWord;
+}
+console.log(findLongestWord(words));
 
 
 // Iteration #3: Calculate the sum
 const numbers = [6, 12, 1, 18, 13, 16, 2, 1, 8, 10];
 
-function sumNumbers() {}
-
+function sumNumbers(numArray) {
+  if (!numArray.length) return 0;
+  let sum = 0;
+  for (const element of numArray) {
+    sum += element;
+  }
+  return sum;
+}
+console.log(sumNumbers(numbers));
 
 
 // Iteration #3.1 Bonus:
-function sum() {}
-
+const mixedArr = [6, 12, 'miami', 1, true, 'barca', '200', 'lisboa', 8, 10];
+function sum(mixArray) {
+  if (!mixArray.length) return 0;
+  let sum = 0;
+  for (const element of mixArray) {
+    if (typeof element === 'number') {
+      sum += element;
+    } else if (typeof element === 'string') {
+      sum += element.length;
+    } else if (typeof element === 'boolean') {
+      sum += Number(element);
+    } else {
+      throw new Error('One of the values is a not supported value')
+    }
+  }
+  return sum;
+}
+console.log(sum(mixedArr));
 
 
 // Iteration #4: Calculate the average
 // Level 1: Array of numbers
 const numbersAvg = [2, 6, 9, 10, 7, 4, 1, 9];
 
-function averageNumbers() {}
-
-
+function averageNumbers(numAvgArray) {
+  if (!numAvgArray.length) return null;
+  return sumNumbers(numAvgArray) / numAvgArray.length;
+}
+console.log(averageNumbers(numbersAvg));
 // Level 2: Array of strings
 const wordsArr = ['seat', 'correspond', 'linen', 'motif', 'hole', 'smell', 'smart', 'chaos', 'fuel', 'palace'];
 
-function averageWordLength() { }
-
+function averageWordLength(wordAvgArray) {
+  if (!wordAvgArray.length) return null;
+  let arrayLength = 0;
+  for (const word of wordAvgArray) {
+    arrayLength += word.length;
+  }
+  return arrayLength / wordAvgArray.length;
+}
+console.log(averageWordLength(wordsArr));
 // Bonus - Iteration #4.1
-function avg() {}
+function avg(mixArray) {
+  if (!mixArray.length) return null;
+  return sum(mixArray) / mixArray.length;
+}
+console.log(avg(mixedArr));
 
 // Iteration #5: Unique arrays
 const wordsUnique = [
@@ -52,15 +102,36 @@ const wordsUnique = [
   'bring'
 ];
 
-function uniquifyArray() {}
-
+function uniquifyArray(stringsArray) {
+  if (!stringsArray.length) return null;
+  const indexOfDuplicates = [];
+  for (let i = stringsArray.length - 1; i >= 0; i--) {
+    const firstTime = stringsArray.indexOf(stringsArray[i], i + 1);
+    if (firstTime !== -1) {
+      indexOfDuplicates.push(firstTime);
+    }
+  }
+  console.log(indexOfDuplicates)
+  for (const index of indexOfDuplicates) {
+    stringsArray.splice(index, 1);
+  }
+  return stringsArray;
+}
+console.log(uniquifyArray(wordsUnique));
 
 
 // Iteration #6: Find elements
 const wordsFind = ['machine', 'subset', 'trouble', 'starting', 'matter', 'eating', 'truth', 'disobedience'];
 
-function doesWordExist() {}
+function doesWordExist(wordsArray, word) {
+  if (!wordsArray.length) return null;
+  if (typeof word != 'string') {
+    throw new Error('The word to find is not a String')
+  }
+  return wordsArray.includes(word);
 
+}
+console.log(doesWordExist(wordsFind, 'subset'))
 
 
 // Iteration #7: Count repetition
@@ -78,8 +149,20 @@ const wordsCount = [
   'matter'
 ];
 
-function howManyTimes() {}
-
+function howManyTimes(wordsArray, word) {
+  if (!wordsArray.length) return 0;
+  if (typeof word != 'string') {
+    throw new Error('The word to find is not a String')
+  }
+  let wordRep = 0;
+  for (const element of wordsArray) {
+    if (element === word) {
+      wordRep++;
+    }
+  }
+  return wordRep;
+}
+console.log(howManyTimes(wordsCount, 'matter'))
 
 
 // Iteration #8: Bonus
@@ -106,10 +189,58 @@ const matrix = [
   [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48]
 ];
 
-function greatestProduct() {}
-
-
+function greatestProduct(bigMatrix) {
+  const rows = bigMatrix.length;
+  const columns = bigMatrix[0].length;
+  let greatestProd = 0;
+
+  for (let i = 0; i < rows; i++) {
+    for (let j = 0; j <= columns - 4; j++) {
+      let rowsProd = bigMatrix[i][j] * bigMatrix[i][j + 1] * bigMatrix[i][j + 2] * bigMatrix[i][j + 3];
+      greatestProd = Math.max(greatestProd, rowsProd);
+    }
+  }
+  for (let i = 0; i <= rows - 4; i++) {
+    for (let j = 0; j < columns; j++) {
+      let columnsProd = bigMatrix[i][j] * bigMatrix[i + 1][j] * bigMatrix[i + 2][j] * bigMatrix[i + 3][j];
+      greatestProd = Math.max(greatestProd, columnsProd);
+    }
+  }
+  return greatestProd;
+}
 
+console.log(greatestProduct(matrix));
+
+//Iteraction #8.2 Bonus 
+function greatestProductOfDiagonals(bigMatrix) {
+  const rows = bigMatrix.length;
+  const columns = bigMatrix[0].length;
+  let greatestProd = 0;
+
+
+  for (let i = 3; i < rows; i++) {
+    for (let j = 3; j < columns; j++) {
+      if (i - 3 >= 0 && j - 3 >= 0) {
+        let diagonalULProd = bigMatrix[i][j] * bigMatrix[i - 1][j - 1] * bigMatrix[i - 2][j - 2] * bigMatrix[i - 3][j - 3];
+        greatestProd = Math.max(greatestProd, diagonalULProd);
+      }
+      if (i - 3 >= 0 && j + 3 < columns) {
+        let diagonalURProd = bigMatrix[i][j] * bigMatrix[i - 1][j + 1] * bigMatrix[i - 2][j + 2] * bigMatrix[i - 3][j + 3];
+        greatestProd = Math.max(greatestProd, diagonalURProd);
+      }
+      if (i + 3 < rows && j - 3 >= 0) {
+        let diagonalDLProd = bigMatrix[i][j] * bigMatrix[i + 1][j - 1] * bigMatrix[i + 2][j - 2] * bigMatrix[i + 3][j - 3];
+        greatestProd = Math.max(greatestProd, diagonalDLProd);
+      }
+      if (i + 3 < rows && j + 3 < columns) {
+        let diagonalDRProd = bigMatrix[i][j] * bigMatrix[i + 1][j + 1] * bigMatrix[i + 2][j + 2] * bigMatrix[i + 3][j + 3];
+        greatestProd = Math.max(greatestProd, diagonalDRProd);
+      }
+    }
+  }
+  return greatestProd;
+}
+console.log(greatestProductOfDiagonals(matrix));
 
 // The following is required to make unit tests work.
 /* Environment setup. Do not modify the below code. */