diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index b22590bc6..482ef8fc2 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -6,9 +6,23 @@
 // or 'list' has mixed values (the function is expected to sort only numbers).
 
 function calculateMedian(list) {
+  if (!Array.isArray(list)) {
+    return null;
+  }
+  list = list.filter((item) => typeof item === "number");
+  if (list.length === 0) {
+    return null;
+  }
+
+  list.sort((a, b) => a - b);
   const middleIndex = Math.floor(list.length / 2);
-  const median = list.splice(middleIndex, 1)[0];
-  return median;
+  const sumOfIndex = list[middleIndex] + list[middleIndex - 1];
+  const middleValue = sumOfIndex / 2;
+  if (list.length % 2 > 0) {
+    return list[middleIndex];
+  } else {
+    return middleValue;
+  }
 }
 
 module.exports = calculateMedian;
diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index 781e8718a..6d179de93 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -1 +1,13 @@
-function dedupe() {}
+function dedupe(arr) {
+  if (arr.length === 0) {
+    return [];
+  }
+  const uniqueSet = new Set(arr);
+  if (arr.length !== uniqueSet.size) {
+    return [...uniqueSet];
+  } else {
+    return [...arr];
+  }
+}
+
+module.exports = dedupe;
diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index d7c8e3d8e..29354af43 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -16,13 +16,57 @@ E.g. dedupe([1, 2, 1]) returns [1, 2]
 // Given an empty array
 // When passed to the dedupe function
 // Then it should return an empty array
-test.todo("given an empty array, it returns an empty array");
+test("given an empty array, it returns an empty array", () => {
+  const arr = [];
+  const emptyArray = dedupe(arr);
+  expect(emptyArray).toEqual([]);
+});
 
 // Given an array with no duplicates
 // When passed to the dedupe function
 // Then it should return a copy of the original array
+test("the function should return the cope of original array when no duplicates of array pass to it", () => {
+  const arr = [2, 3, 4, 5];
 
+  const result = dedupe(arr);
+  expect(result).toEqual(arr);
+  expect(result).not.toBe(arr);
+});
+test("the function should return the cope of original array when no duplicates of array pass to it ", () => {
+  const arr = [13, 9, 8, 7];
+
+  const result = dedupe(arr);
+  expect(result).toEqual(arr);
+  expect(result).not.toBe(arr);
+});
 // Given an array of strings or numbers
 // When passed to the dedupe function
-// Then it should return a new array with duplicates removed while preserving the 
+// Then it should return a new array with duplicates removed while preserving the
 // first occurrence of each element from the original array.
+test("the function should return the first occurrence of each element when duplicated arrays of element pass to it", () => {
+  const arr = [3, 3, 3, 7, 8, 9, 9, 6, 6];
+
+  const newResult = dedupe(arr);
+  expect(newResult).toEqual([3, 7, 8, 9, 6]);
+});
+test("the function should return the first occurrence of each element when duplicated arrays of element pass to it", () => {
+  const arr = [3, 3, "hi", 8, 8, "hi", "you", 8, "you", "hi"];
+
+  const newResult = dedupe(arr);
+  expect(newResult).toEqual([3, "hi", 8, "you"]);
+});
+test("the function should return the first occurrence of each element when duplicated arrays of element pass to it", () => {
+  const arr = [
+    "orange",
+    "egg",
+    "egg",
+    "banana",
+    "orange",
+    "apple",
+    "banana",
+    "apple",
+  ];
+
+  const newResult = dedupe(arr);
+  expect(newResult).toEqual(["orange", "egg", "banana", "apple"]);
+});
diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js
index 6dd76378e..ccd036cfe 100644
--- a/Sprint-1/implement/max.js
+++ b/Sprint-1/implement/max.js
@@ -1,4 +1,20 @@
 function findMax(elements) {
+  if (elements.length === 0) {
+    return Infinity;
+  } else if (elements.length === 1) {
+    return elements[0];
+  }
+  const number = elements.filter((value) => typeof value === "number");
+  if (number.length === 0) {
+    return undefined;
+  }
+  let max = elements[0];
+  for (let i = 0; i < elements.length; i++) {
+    if (max < elements[i]) {
+      max = elements[i];
+    }
+  }
+  return max;
 }
 
 module.exports = findMax;
diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index 82f18fd88..d6f406b7e 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -16,28 +16,73 @@ const findMax = require("./max.js");
 // When passed to the max function
 // Then it should return -Infinity
 // Delete this test.todo and replace it with a test.
-test.todo("given an empty array, returns -Infinity");
+test("when given an empty array to the function it returns Infinity", () => {
+  const elements = [];
+
+  const result = findMax(elements);
+  expect(result).toEqual(Infinity);
+});
 
 // Given an array with one number
 // When passed to the max function
 // Then it should return that number
-
+test("when the given is array of one number it should return that number", () => {
+  const elements = [30];
+  const result = findMax(elements);
+  expect(result).toEqual(30);
+});
 // Given an array with both positive and negative numbers
 // When passed to the max function
 // Then it should return the largest number overall
-
+test("should return the largest number when the array contains both negative and positive numbers", () => {
+  const elements = [-10, -12, -7, 0, 2, 4];
+  const result = findMax(elements);
+  expect(result).toEqual(4);
+});
+test("should return the largest number when the array contains both negative and positive numbers", () => {
+  const elements = [-20, -6, -2, 0, 7, 9, 5];
+  const result = findMax(elements);
+  expect(result).toEqual(9);
+});
 // Given an array with just negative numbers
 // When passed to the max function
 // Then it should return the closest one to zero
-
+test("should return number that is closest to zero when the array contains all negative numbers", () => {
+  const elements = [-20, -6, -2, -4, -7, -9, -5];
+  const result = findMax(elements);
+  expect(result).toEqual(-2);
+});
+test("should return number that is closest to zero when the array contains all negative numbers", () => {
+  const elements = [-20, -11, -1, 0, -7, -9, -5];
+  const result = findMax(elements);
+  expect(result).toEqual(0);
+});
 // Given an array with decimal numbers
 // When passed to the max function
 // Then it should return the largest decimal number
-
+test("should return the largest decimal number when the array contains decimal numbers", () => {
+  const elements = [2.7, 6.3, 7.3, 4.9, 7.9, 4.5];
+  const result = findMax(elements);
+  expect(result).toEqual(7.9);
+});
+test("should return the largest decimal number when the array contains decimal numbers", () => {
+  const elements = [11.8, 16.3, 27.3, 41.9, 0.9, 14.5];
+  const result = findMax(elements);
+  expect(result).toEqual(41.9);
+});
 // Given an array with non-number values
 // When passed to the max function
 // Then it should return the max and ignore non-numeric values
-
+test("should return the largest number ignoring non-numerical values when the array contains non-numerical value", () => {
+  const elements = [11, "apple", 27, "hi", 9, "zero"];
+  const result = findMax(elements);
+  expect(result).toEqual(27);
+});
 // Given an array with only non-number values
 // When passed to the max function
 // Then it should return the least surprising value given how it behaves for all other inputs
+test("should return only number value, when the array contains non-numerical value", () => {
+  const elements = ["apple", "hi", "book", "zero"];
+  const result = findMax(elements);
+  expect(result).toEqual(undefined);
+});
diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js
index 9062aafe3..e7f6cdbd9 100644
--- a/Sprint-1/implement/sum.js
+++ b/Sprint-1/implement/sum.js
@@ -1,4 +1,19 @@
 function sum(elements) {
+  if (elements.length === 0) {
+    return 0;
+  }
+  const number = elements.filter((value) => typeof value === "number");
+  if (number.length === 0) {
+    return undefined;
+  }
+  if (elements.length === 1) {
+    return elements[0];
+  }
+  let arraySum = 0;
+  for (let i = 0; i < number.length; i++) {
+    arraySum += number[i];
+  }
+  return arraySum;
 }
 
 module.exports = sum;
diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index dd0a090ca..ae3fbe97a 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -13,24 +13,60 @@ const sum = require("./sum.js");
 // Given an empty array
 // When passed to the sum function
 // Then it should return 0
-test.todo("given an empty array, returns 0")
+test("when empty array is given it should returns 0", () => {
+  const elements = [];
+  const result = sum(elements);
+  expect(result).toEqual(0);
+});
 
 // Given an array with just one number
 // When passed to the sum function
 // Then it should return that number
-
+test("when array with just one number given it should returns that number", () => {
+  const elements = [13];
+  const result = sum(elements);
+  expect(result).toEqual(13);
+});
+test("when array with just one number given it should returns that number", () => {
+  const elements = [9];
+  const result = sum(elements);
+  expect(result).toEqual(9);
+});
 // Given an array containing negative numbers
 // When passed to the sum function
 // Then it should still return the correct total sum
-
+test("when array with negative numbers given it should return the correct total sum", () => {
+  const elements = [-9, -2, -4, -7];
+  const result = sum(elements);
+  expect(result).toEqual(-22);
+});
+test("when array with negative numbers given it should return the correct total sum", () => {
+  const elements = [-11, -9, -2, -5];
+  const result = sum(elements);
+  expect(result).toEqual(-27);
+});
 // Given an array with decimal/float numbers
 // When passed to the sum function
 // Then it should return the correct total sum
-
+test("when array that contain decimal or float number pass to the function it should return the correct total sum", () => {
+  const elements = [0.9, 1 / 2, 4.3, 3.7, 1 / 4];
+  const result = sum(elements);
+  expect(result).toEqual(9.649999999999999);
+});
 // Given an array containing non-number values
 // When passed to the sum function
 // Then it should ignore the non-numerical values and return the sum of the numerical elements
+test("when array that contain number and non-number pass to the function it should return the sum of the numerical elements", () => {
+  const elements = [9, 1, 4, "one", 3, "two", 4];
+  const result = sum(elements);
+  expect(result).toEqual(21);
+});
 
 // Given an array with only non-number values
 // When passed to the sum function
 // Then it should return the least surprising value given how it behaves for all other inputs
+test("when array that contain non-number pass to the function it should return undefined", () => {
+  const elements = ["window", "one", "name", "two"];
+  const result = sum(elements);
+  expect(result).toEqual(undefined);
+});
diff --git a/Sprint-1/refactor/includes.js b/Sprint-1/refactor/includes.js
index 29dad81f0..994131c59 100644
--- a/Sprint-1/refactor/includes.js
+++ b/Sprint-1/refactor/includes.js
@@ -1,8 +1,7 @@
 // Refactor the implementation of includes to use a for...of loop
 
 function includes(list, target) {
-  for (let index = 0; index < list.length; index++) {
-    const element = list[index];
+  for (let element of list) {
     if (element === target) {
       return true;
     }