diff --git a/src/advanced/advanced.js b/src/advanced/advanced.js
index 8b2b193..561a321 100644
--- a/src/advanced/advanced.js
+++ b/src/advanced/advanced.js
@@ -6,21 +6,53 @@ const nums = [1, 10, 3, 9, 4, 8, 5, 7, 6, 2, -5, -2, -4, -9] // eslint-disable-l
 let hasTen = false
 let indexOfTen = -1
 
+for (let i = 0; i <= nums.length; i++) {
+  if (nums.includes(10)) hasTen = true
+  indexOfTen = nums.indexOf(10)
+}
+
 // 2. Use a for loop to count how many numbers in the array are divisible by 3
 let divisibleByThreeCount = 0
 
+for (let i = 0; i <= nums.length; i++) {
+  if (nums[i] % 3 === 0) {
+    divisibleByThreeCount++
+  }
+}
+
 // 3. use a for loop to find the average of the numbers in the array
-let average = 0
+let sum = 0
+for (let i = 0; i < nums.length; i++) {
+  sum += nums[i]
+}
+const average = sum / nums.length
 
 // 4. use a for loop to find the largest number in the array
 let largest = 0
 
+for (let i = 0; i <= nums.length; i++) {
+  if (nums[i] > largest) largest = nums[i]
+}
+
 // 5. use a for loop to find the smallest number in the array
 let smallest = 100000
 
+for (let i = 0; i <= nums.length; i++) {
+  if (nums[i] < smallest) smallest = nums[i]
+}
+
 // 6. find the median of the numbers in the array
 let median = 0
 
+nums.sort((a, b) => a - b)
+const mid = Math.floor(nums.length / 2)
+
+if (nums.length % 2 === 0) {
+  median = nums[mid - 1]
+} else {
+  median = nums[mid]
+}
+
 module.exports = {
   hasTen,
   indexOfTen,
diff --git a/src/extensions/nested-loops.js b/src/extensions/nested-loops.js
index 1d0044b..53286d5 100644
--- a/src/extensions/nested-loops.js
+++ b/src/extensions/nested-loops.js
@@ -13,21 +13,54 @@ const deepThree = []
 
 // HINT: in the below loop, the statements and block of code needs to be changed
 // HINT: in the below loop, the var i represents the loop index
-// for (let i = 5; i < 7; i++) {
-// Your code here
-// }
+for (let i = START; i <= END; i++) {
+  simpleOne.push(i)
+}
 
 // 2. Using nested for loops, add arrays to 'nestedOne' where each array has n copies of the outer 'loop index'
 //    eg [[1],[2,2],...]
-
+for (let i = 1; i <= 10; i++) {
+  const innerArray = []
+  for (let j = 0; j < i; j++) {
+    innerArray.push(i)
+  }
+  nestedOne.push(innerArray)
+}
 // 3. As 2, but each array should contain the values from the outer 'loop index' to 1 inclusive. Update array 'nestedTwo'
 //    eg [[1],[2,1],...]
+for (let i = 1; i <= 10; i++) {
+  const innerArray = []
+  for (let j = i; j >= 1; j--) {
+    innerArray.push(j)
+  }
+  nestedTwo.push(innerArray)
+}
 
 // 4. As 2, but each array should contain arrays from 1 to the outer 'loop index' with the value of the outer 'loop index'. Update array 'deepOne'
 //    eg [[[1]],[[2],[2,2]],...]
+for (let i = 1; i <= 10; i++) {
+  const outerArray = []
+  for (let j = 1; j <= i; j++) {
+    const innerArray = new Array(j)
+    innerArray.fill(i)
+    outerArray.push(innerArray)
+  }
+  deepOne.push(outerArray)
+}
 
 // 5. As 4, update array 'deepTwo' so that the result is:
 //       [[[1]],[[1],[1,2]],...]
+for (let i = 1; i <= 10; i++) {
+  const outerArray = []
+  for (let j = 1; j <= i; j++) {
+    const innerArray = []
+    for (let k = 1; k <= j; k++) {
+      innerArray.push(k)
+    }
+    outerArray.push(innerArray)
+  }
+  deepTwo.push(outerArray)
+}
 
 // 6. As 5, update the array 'deepThree', but the result should be the average of the sum of the squares of the numbers in each array
 //       [[1],[[1],[2.5]],...]
diff --git a/src/for-loop-and-arrays.js b/src/for-loop-and-arrays.js
index 6635155..116cdad 100644
--- a/src/for-loop-and-arrays.js
+++ b/src/for-loop-and-arrays.js
@@ -6,18 +6,37 @@ let word = '' // eslint-disable-line prefer-const
 // TODO: Add code below this line to make the tests pass
 
 // 1. Use a for loop to set the sum variable to the sum of all the values in nums
+for (let i = 0; i < nums.length; i++) {
+  sum += nums[i]
+}
 
 // 2. Use a for loop to populate doubledNums with every value from nums array doubled (i.e [2, 6, 24, etc...])
 const doubledNums = []
 
+for (let i = 0; i < nums.length; i++) {
+  doubledNums.push(nums[i] * 2)
+}
+
 // 3. Use a for loop to set word variable equal to all the letters in the letters array combined as a single string
+for (let i = 0; i < letters.length; i++) {
+  word += letters[i]
+}
 
 // 4. Use a for loop to populate everySecondNum with every second number from the nums array
 const everySecondNum = []
 
+for (let i = 0; i < nums.length - 1; i++) {
+  everySecondNum.push(nums[i + 1])
+  i++
+}
+
 // 5. Use a for loop to populate numsReversed with the numbers from nums in reverse order
 const numsReversed = []
 
+for (let i = nums.length - 1; i >= 0; i--) {
+  numsReversed.push(nums[i])
+}
+
 // do not change below this line
 module.exports = {
   a: sum,
diff --git a/src/for-loop-basic.js b/src/for-loop-basic.js
index dc3775a..f92c97c 100644
--- a/src/for-loop-basic.js
+++ b/src/for-loop-basic.js
@@ -4,13 +4,28 @@ const evenNums = []
 const countdown = []
 
 // TODO: 1. Write a for loop that adds the numbers 0 to 3 to the numsZeroToThree array
+for (let i = 0; i < 4; i++) {
+  numsZeroToThree.push(i)
+}
 
 // TODO: 2. Write a for loop that adds the numbers 5 to 10 to the numsFiveToTen array
 
+for (let i = 5; i < 11; i++) {
+  numsFiveToTen.push(i)
+}
+
 // TODO: 3. Write a for loop that adds all the even numbers between 0 and 6 (0, 2, 4, 6) to evenNums
 
+for (let i = 0; i < 7; i++) {
+  evenNums.push(i)
+  i++
+}
+
 // TODO: 4. Write a for loop that adds the numbers 3 to 0 (in that order) to the countdown array
 
+for (let i = 3; i >= 0; i--) {
+  countdown.push(i)
+}
 // do not change below this line
 module.exports = {
   a: numsZeroToThree,