diff --git a/src/main/java/com/booleanuk/core/Exercise.java b/src/main/java/com/booleanuk/core/Exercise.java
index 4d002b4..534acf3 100644
--- a/src/main/java/com/booleanuk/core/Exercise.java
+++ b/src/main/java/com/booleanuk/core/Exercise.java
@@ -22,7 +22,7 @@ public int[] one() {
         // E.g. The first value is at index 0, the second at index 1, the third at index 2.
         // Using an index, change the number 17 in the numbers array to 68
         // WRITE YOUR CODE BETWEEN THIS LINE...
-
+        numbers[2] = 68;
 
 
         // ... AND THIS LINE
@@ -37,7 +37,7 @@ public String two() {
         // teacher contained in the teachers array
         // WRITE YOUR CODE BETWEEN THIS LINE...
 
-        String teacher = "";
+        String teacher = teachers[3];
 
         // ... AND THIS LINE
 
@@ -47,14 +47,13 @@ public String two() {
     public String[] three() {
         // 3. Create a string array named cars that contains three names of car manufacturers: Audi, BMW and Dodge
         // WRITE YOUR CODE BETWEEN THIS LINE...
-
+        String[] cars = {"Audi", "BMW", "Dodge"};
 
 
         // ... AND THIS LINE
 
         // Then change the code below to remove the dummyArray completely and return the cars array you created above instead.
-        String[] dummyArray = {};
-        return dummyArray;
+        return cars;
     }
 
     public int four() {
@@ -63,24 +62,25 @@ public int four() {
         // 4. Using array indices, set the value of the result variable below to the
         // sum of every number in the numbers array
         // WRITE YOUR CODE BETWEEN THIS LINE...
-
-        int result = 0;
+        int test = 0;
+        for (int number : numbers) {
+            test += number;
+        }
 
         // ... AND THIS LINE
 
-        return result;
+        return test;
     }
 
     public float[] five() {
         // 5. Create an array called floats that contains 3 floating point numbers: 9.62, 23.17 and 3.14
         // WRITE YOUR CODE BETWEEN THIS LINE...
 
-
+        float[] floats = {9.62f, 23.17f, 3.14f};
 
         // ... AND THIS LINE
 
         // Then change the code below to remove the dummyArray completely and return the floats array you created instead
-        float[] dummyArray = {};
-        return dummyArray;
+        return floats;
     }
 }