diff --git a/src/functions-and-arrays.js b/src/functions-and-arrays.js
index 3a7dbec41..1f1f4b9a9 100644
--- a/src/functions-and-arrays.js
+++ b/src/functions-and-arrays.js
@@ -1,41 +1,156 @@
 // Iteration #1: Find the maximum
-function maxOfTwoNumbers() {}
-
-
+function maxOfTwoNumbers(num1, num2) {
+  if (num1 > num2) {
+    return num1;
+    } else {
+      return num2;
+      }
+}
 
 // Iteration #2: Find longest word
 const words = ['mystery', 'brother', 'aviator', 'crocodile', 'pearl', 'orchard', 'crackpot'];
 
-function findLongestWord() {}
+function findLongestWord(wordsArr) {
+  if (wordsArr.length === 0) {
+    return null;
+
+    }
+  
+  let longest = '';
+
+  for (let i = 0; i < wordsArr.length; i ++) {
+    if (wordsArr[i].length > longest.length) {
+      longest = wordsArr[i];
+
+    }
+  }
+
+  return longest;
+}
 
 
 
 // Iteration #3: Calculate the sum
 const numbers = [6, 12, 1, 18, 13, 16, 2, 1, 8, 10];
 
-function sumNumbers() {}
+function sumNumbers(numbersArray) {
+  let sum = 0;
+
+  for(let i = 0; i < numbersArray.length; i++) {
+    sum += numbersArray[i];
+  }
+
+  return sum;
+}
 
 
 
 // Iteration #3.1 Bonus:
-function sum() {}
+function sum(array) {
+  if (array.length === 0) {
+    return 0;
+  }
+
+  let total = 0;
+
+  for (let i = 0; i < array.length; i++) {
+    let item = array[i];
+
+    //Si es número
+    if (typeof item === 'number') {
+      total += item;
+    }
+
+
+    // Si es string
+    else if (typeof item === 'string') {
+      total += item.length;
+    }
+
+    //Si es booleano
+    else if (typeof item === 'boolean') {
+      total += item ? 1 : 0;
+    }
 
+    // Si es tipo no soportado (objeto o array)
+    else {
+      throw new Error ("tipo de dato no admitido")
+    }
+  }
 
+  return total
+
+}
 
 // Iteration #4: Calculate the average
 // Level 1: Array of numbers
-const numbersAvg = [2, 6, 9, 10, 7, 4, 1, 9];
+const numbersAvg = [2, 6, 9, 10, 7, 4, 1, 9]; 
+
+
+  function averageNumbers(numbers) {
+  if (numbers.length === 0) {
+    return null;
+}
+
+let sum = 0
+
+for (let i = 0; i < numbers.length; i++) {
+  sum += numbers[i];
+}
 
-function averageNumbers() {}
+return sum / numbers.length
+
+}
 
 
 // Level 2: Array of strings
 const wordsArr = ['seat', 'correspond', 'linen', 'motif', 'hole', 'smell', 'smart', 'chaos', 'fuel', 'palace'];
 
-function averageWordLength() { }
+function averageWordLength(words) {
+  if (!Array.isArray(words) || words.length === 0) return null 
+
+  let totalLength = 0
+
+  for (let i = 0; i < words.length; i++) {
+    if (typeof words[i] !== 'string') throw new Error ("Tipo de entrada no válido")
+      totalLength += words[i].length;
+  }
+
+  return totalLength / words.length;
+}
+
+
 
 // Bonus - Iteration #4.1
-function avg() {}
+function avg(arr) {
+  if (!Array.isArray(arr) || arr.length === 0) return null
+
+  let total = 0;
+  let count = 0;
+
+  for (let i = 0; i < arr.length; i++) {
+    let item = arr[i];
+
+    if (typeof item === 'number') {
+      total += item;
+      count++;
+    } else if (typeof item === 'string') {
+      total += item.length
+      count++;
+    } else if (typeof item === 'boolean') {
+      total += item ? 1 : 0;
+      count++;
+    } else {
+      throw new Error ("Tipo de datos no admitido");
+    }
+
+ }
+
+ return total / count;
+
+}
+
+
 
 // Iteration #5: Unique arrays
 const wordsUnique = [
@@ -52,14 +167,30 @@ const wordsUnique = [
   'bring'
 ];
 
-function uniquifyArray() {}
+function uniquifyArray(words) {
+  if (!Array.isArray(words) || words.length === 0) return null;
+
+  const uniqueWords = [];
+
+  for (let i = 0; i < words.length; i++) {
+    if (!uniqueWords.includes(words[i])) {
+      uniqueWords.push(words[i]);
+    }
+
+  }
 
+  return uniqueWords
 
+}
 
 // Iteration #6: Find elements
 const wordsFind = ['machine', 'subset', 'trouble', 'starting', 'matter', 'eating', 'truth', 'disobedience'];
 
-function doesWordExist() {}
+function doesWordExist(words, wordToFind) {
+  if (!Array.isArray(words) || words.length === 0) return null;
+  return words.includes(wordToFind);
+
+}
 
 
 
@@ -78,7 +209,19 @@ const wordsCount = [
   'matter'
 ];
 
-function howManyTimes() {}
+function howManyTimes(words, wordToCount) {
+  if (!Array.isArray(words)  || words.length === 0) return 0;
+
+  let count = 0;
+
+  for (let i = 0; i < words.length; i++) {
+    if (words[i] === wordToCount) {
+      count++;
+    }
+  }
+
+  return count;
+}
 
 
 
@@ -106,7 +249,44 @@ 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(matrix) {
+  if (!Array.isArray(matrix) || matrix.length === 0) return 0;
+
+  let maxProduct = 0;
+
+  for (let row = 0; row < matrix.length; row++) {
+    for (let col = 0; col < matrix[row].length; col++) {
+
+    // Horizontal
+    if (col + 3 < matrix[row].length)  {
+      const HorizProduct =
+      matrix[row][col] *
+      matrix[row][col + 1] *
+      matrix[row][col + 2] *
+      matrix[row][col + 3]
+
+      if (HorizProduct > maxProduct) maxProduct = HorizProduct;
+  }
+
+
+  // Vertical
+  if (row + 3 < matrix.length) {
+    const vertProduct =
+    matrix[row][col] *
+    matrix[row + 1][col] *
+    matrix[row + 2][col] *
+    matrix[row + 3][col];
+
+
+    if (vertProduct > maxProduct) maxProduct = vertProduct;
+
+  }
+  }
+}
+
+return maxProduct
+
+}