diff --git a/src/main/java/com/booleanuk/core/Exercise.java b/src/main/java/com/booleanuk/core/Exercise.java
index 0f97fe4..e1458c8 100644
--- a/src/main/java/com/booleanuk/core/Exercise.java
+++ b/src/main/java/com/booleanuk/core/Exercise.java
@@ -1,9 +1,10 @@
 package com.booleanuk.core;
 
 public class Exercise {
-    public int[] numsZeroToThree;
-    public int[] numsFiveToTen;
-    public int[] countdown;
+    public int[] numsZeroToThree = new int[4];
+
+    public int[] numsFiveToTen = new int [6];
+    public int[] countdown= new int[4];
 
     public int[] favouriteNumbers = {1, 2, 4, 5, 7, 8, 10};
 
@@ -11,35 +12,57 @@ public class Exercise {
 
     public void stepOne() {
         // TODO: 1. Write a for loop that adds the numbers 0 to 3 to the numsZeroToThree array
-
+        for (int i = 0; i <= 3; i++) {
+            numsZeroToThree[i] = i;
+        }
 
     }
 
     public void stepTwo() {
         // TODO: 2. Write a for loop that adds the numbers 5 to 10 to the numsFiveToTen array
-
+        for (int i = 5; i <= 10; i++) {
+            numsFiveToTen[i - 5] = i;
+        }
 
     }
 
     public void stepThree() {
         // TODO: 3. Write a for loop that adds the numbers 3 to 0 (in that order) to the countdown array
-
+        int b = 0;
+        for(int i = 3; i > 0; i--){
+            countdown[b] = i;
+            b = b + 1;
+        }
 
     }
 
     public boolean stepFour(int num) {
         // TODO: 6. Write a for loop that checks if num is in the favouriteNumbers array
-
-
-
-        return false;
+        boolean b = false;
+        for (int i = 0; i < favouriteNumbers.length; i++){
+            if (favouriteNumbers[i] == num){
+                b = true;
+            }
+        }
+        if (b){
+            return true;
+        } else {
+            return false;
+        }
     }
 
     public boolean stepFive(String hobby) {
         // TODO 5. Write a for loop that checks if the hobby String is in the myHobbies array
-
-
-
-        return false;
+        boolean b = false;
+        for(int i = 0; i < myHobbies.length; i++){
+            if(myHobbies[i].equals(hobby)){
+                b = true;
+            }
+        }
+        if (b){
+            return true;
+        } else {
+            return false;
+        }
     }
-}
+}
\ No newline at end of file
diff --git a/src/main/java/com/booleanuk/extension/Extension.java b/src/main/java/com/booleanuk/extension/Extension.java
index 8b9d4a6..4d8fb63 100644
--- a/src/main/java/com/booleanuk/extension/Extension.java
+++ b/src/main/java/com/booleanuk/extension/Extension.java
@@ -1,12 +1,15 @@
 package com.booleanuk.extension;
 
 public class Extension {
-    public int[] numsEven;
+    public int[] numsEven=new int[4];
 
     public void stepOne() {
+         int num=0;
         // TODO: 1. Write a for loop that adds all the even numbers between 0 and 6 (0, 2, 4, 6) to evenNums
-
-
+        for (int i=0;i<=3;i++) {
+            numsEven[i] = num;
+            num += 2;
+        }
         
     }
 }