diff --git a/src/main/java/com/booleanuk/core/Exercise.java b/src/main/java/com/booleanuk/core/Exercise.java
index 70ac307..76e27f4 100644
--- a/src/main/java/com/booleanuk/core/Exercise.java
+++ b/src/main/java/com/booleanuk/core/Exercise.java
@@ -40,60 +40,72 @@ public String sayGoodMorning(boolean isMorning) {
     // 1. What will the returned value be if I run sayGoodMorning(false)?
     // Change the returned value in the method below to your answer. It is case-sensitive.
     public String one() {
-        return "";
+        return "Good day!";
     }
 
     // 2. What will the output be if I run sayGoodMorning(true)?
     // Change the returned value in the method below to your answer. It is case-sensitive.
     public String two() {
-        return "";
+        return "Good morning!";
     }
 
     // 3. What will the output be if I run sayGoodMorning("Hello".equals("Hello"))?
     // Change the returned value in the method below to your answer. It is case-sensitive.
     public String three() {
-        return "";
+        return "Good morning!";
     }
 
     // 4. What will the output be if I run sayGoodMorning(!"A word".equals("Another word"))
     public String four() {
-        return "";
+        return "Good morning!";
     }
 
     // 5. What will the output be if I run sayGoodMorning(25 != 25)
     public String five() {
-        return "";
+        return "Good day!";
     }
 
     // 6. Use a conditional statement to return "Correct!" if the input is more than 7
     // or "Wrong!" if not
     public String six(int num) {
-        return "Not implemented yet!";
+        if (num > 7){
+            return "Correct!";
+        } else {
+            return "Wrong!";
+        }
     }
 
     // 7. Use a conditional statement to return "Correct!" if the input is false
     // or "Wrong!" if not
     public String seven(boolean bool) {
-        return "Not implemented yet!";
+        if (bool){
+            return "Wrong!";
+        } else {
+            return "Correct!";
+        }
     }
 
     // 8. Use a conditional statement to return "Correct!" if numOne is more than or equal to numTwo
     // or "Wrong!" if not
     public String eight(int numOne, int numTwo) {
-        return "Not implemented yet!";
+        if (numOne >= numTwo){
+            return "Correct!";
+        } else {
+            return "Wrong!";
+        }
     }
 
     // 9. Use a conditional statement to return true if the array provided is not empty
     // or false if it is empty
     public boolean nine(int[] nums) {
-        return false;
+        return nums.length != 0;
     }
 
     // 10. Use a conditional statement to return true if the provided string contains the word
     // "milk", or false if not
     // https://www.w3schools.com/java/java_ref_string.asp
     public boolean ten(String sentence) {
-        return false;
+        return sentence.contains("milk");
     }
 
     // 11. Use conditional statements to return the number 3 if the provided string contains
@@ -101,13 +113,21 @@ public boolean ten(String sentence) {
     // Return the number 9 if the string contains both coffee and milk.
     // Otherwise, return the number 0.
     public int eleven(String sentence) {
-        return -1;
+        if (sentence.contains("milk") && !sentence.contains("coffee")){
+            return 3;
+        } else if (sentence.contains("coffee") && !sentence.contains("milk")){
+            return 6;
+        } else if (sentence.contains("milk") && sentence.contains("coffee")){
+            return 9;
+        } else {
+            return 0;
+        }
     }
 
     // 12. Use conditional statements to return true if num is more than or equal to lower and is
     // less than or equal to upper, otherwise return false.
     public boolean twelve(int num, int lower, int upper) {
-        return false;
+        return (upper >= num && num >= lower);
     }
 
     /*
@@ -123,6 +143,16 @@ public boolean twelve(int num, int lower, int upper) {
         20+     | Adult
      */
     public String thirteen(int age) {
-        return "Not implemented yet!";
+        if (age == 0){
+            return "Baby";
+        } else if (age <= 4){
+            return "Toddler";
+        } else if (age <= 12){
+            return "Child";
+        } else if (age <= 19){
+            return "Teenager";
+        } else {
+            return "Adult";
+        }
     }
 }
diff --git a/src/main/java/com/booleanuk/extension/Extension.java b/src/main/java/com/booleanuk/extension/Extension.java
index 44e540f..14cbaf4 100644
--- a/src/main/java/com/booleanuk/extension/Extension.java
+++ b/src/main/java/com/booleanuk/extension/Extension.java
@@ -13,6 +13,15 @@ public class Extension extends ExtensionBase {
         "The cake is still baking!" if there are any remaining minutes left,
         and "The timer finished ages ago!" if the remaining minutes is a negative number
      */
+    public String timerStatus(int minLeft){
+        if (minLeft == 0){
+            return "The cake is ready!";
+        } else if (minLeft > 0){
+            return "The cake is still baking!";
+        } else {
+            return "The timer finished ages ago!";
+        }
+    }
 
 
 
@@ -26,6 +35,13 @@ public class Extension extends ExtensionBase {
         provided and the prep time per ingredient.
         If a prep time of 0 is provided, the method should assume each ingredient takes 2 minutes to prepare.
      */
+    public int estimatePrepTime(String[] ingredients, int preptime){
+        if (preptime == 0){
+            return ingredients.length * 2;
+        } else {
+            return ingredients.length * preptime;
+        }
+    }
 
 
 
@@ -40,6 +56,20 @@ public class Extension extends ExtensionBase {
 
         You may need to use programming techniques we have yet to cover in the course to solve this task.
      */
+    public int calculateGramsOfSugar(String[] ingredients, int layers){
+        if (ingredients.length != 3){
+            throw new IllegalArgumentException("Cake must have exactly 3 ingredients.");
+        }
+
+        for (int i = 0; i < ingredients.length; i++){
+            if (ingredients[i].equals("sugar")){
+                return 100 * layers;
+            }
+        }
+
+        return 0;
+
+    }