diff --git a/Boolean.CSharp.Main/Core.cs b/Boolean.CSharp.Main/Core.cs
index e09c536..ed31352 100644
--- a/Boolean.CSharp.Main/Core.cs
+++ b/Boolean.CSharp.Main/Core.cs
@@ -30,7 +30,7 @@ public Car(string Make)
                 }
             */
             
-            Car car = new Car("Volkswagen");
+            Car car = new Car("Volkswagen", "IDK cars");
             /*  When the car in instantiated, the constructor is passed a string
              in this case Volkswagen which is a Make of car is passed in.
              Within the constructor the 'string Make' variable has scope within the constructor and assiged to the _make member now visible to the whole class
@@ -108,7 +108,7 @@ public Unicycle Question4()
             
             //TIP  see we already have an internal member for the unicyclist name:  _nameOfUnicyclist so you can use this to store the name internally
             //      it is good practice to name internal class variable with an _ at the beginning
-            Unicycle unicycle = new Unicycle();
+            Unicycle unicycle = new Unicycle("Nikolai L. Børseth");
                       
             
 
@@ -132,11 +132,11 @@ What are the parameters and types?
              */
             Aeroplane plane = new Aeroplane();            
             plane.FlightDetails("LHR", "JFK");
-            
+
             //TODO:  5.  Call the FlightDetails method that sets the cancelled message and  cancel the flight
-           
-           //write code here 
 
+            //write code here 
+            plane.FlightDetails("No plane for you");
             return plane;
         }
 
diff --git a/Boolean.CSharp.Main/Extension.cs b/Boolean.CSharp.Main/Extension.cs
index 80c1db6..335d7b0 100644
--- a/Boolean.CSharp.Main/Extension.cs
+++ b/Boolean.CSharp.Main/Extension.cs
@@ -7,23 +7,59 @@
 namespace Boolean.CSharp.Main
 {
     public class Extension
-    {        
+    {
 
         //Implement the following methods:
 
         //TODO: 1. add, which accepts two floats and returns a float (both floats added together)
+        public float add(float a, float b) {
+            return a + b;
+        }
 
         //TODO: 2. add, which accepts two doubles and returns a double (both doubles added together)
+        public double add(double a, double b)
+        {
+            return a + b;
+        }
 
         //TODO: 3. subtract, which accepts two floats and returns a float (first float minus second float)      
+        public float subtract(float a, float b)
+        {
+            return a - b;
+        }
 
         //TODO: 4. subtract, which accepts a String and a char and returns a string with all instances of the provided char removed        
+        public string subtract(string a, char b)
+        {
+            return a.Replace(char.ToString(b), "");
+        }
+
 
         //TODO: 5. multiply, which accepts two ints and returns an int (first int multiplied by second int)
+        public int multiply(int a, int b)
+        {
+            return a * b;
+        }
 
         //TODO: 6. multiply, which accepts a string and an int, and returns a string containing the provided string as many times as the provided int separated by a comma. E.g. multiply("Hello", 3) -> "Hello,Hello,Hello"
-      
+        public string multiply(string a, int b)
+        {
+            string result = a;
+            for (int i = 1; i < b; i++)
+            {
+                result += "," + a;
+            }
+            return result;
+        }
         //TODO: 7. multiply, which accepts an array of Strings that each contain a number, and an int. The method should return an array of ints that contain the value of multiplying each String number by the provided int E.g. multiply(["2", "7", "3"], 3) -> [6, 21, 9]
-
+        public int[] multiply(string[] a, int b)
+        {
+            int[] result = new int[a.Length];
+            for (int i = 0; i < a.Length; i++)
+            {
+                result[i] = b * Int32.Parse(a[i]);
+            }
+            return result;
+        }
     }
 }
diff --git a/Boolean.CSharp.Main/Misc/Bicycle.cs b/Boolean.CSharp.Main/Misc/Bicycle.cs
index f218c0e..7d59370 100644
--- a/Boolean.CSharp.Main/Misc/Bicycle.cs
+++ b/Boolean.CSharp.Main/Misc/Bicycle.cs
@@ -11,5 +11,9 @@ public class Bicycle
         private int _wheelCount;
 
         public int WheelCount { get; set; }
+
+        public Bicycle() {
+            this.WheelCount = 2;
+        }
     }
 }
diff --git a/Boolean.CSharp.Main/Misc/Car.cs b/Boolean.CSharp.Main/Misc/Car.cs
index d810f5f..eae974a 100644
--- a/Boolean.CSharp.Main/Misc/Car.cs
+++ b/Boolean.CSharp.Main/Misc/Car.cs
@@ -23,6 +23,12 @@ public Car(string Make)
             _model = string.Empty;
         }
 
+        public Car(string Make, string Model)
+        {
+            _make = Make;
+            _model = Model;
+        }
+
         public string Make
         {
             get => _make;
diff --git a/Boolean.CSharp.Main/Misc/Motorbike.cs b/Boolean.CSharp.Main/Misc/Motorbike.cs
index 6fcf20b..aef5667 100644
--- a/Boolean.CSharp.Main/Misc/Motorbike.cs
+++ b/Boolean.CSharp.Main/Misc/Motorbike.cs
@@ -11,11 +11,10 @@ public class Motorbike
     {
         private string _make;
         private string _model;
-        private int _cc = 0;
+        private int _cc = 373;
 
         public Motorbike()
         {
-            _cc = 373;
             _make = string.Empty;
             _model = string.Empty;
         }
diff --git a/Boolean.CSharp.Main/Misc/Unicycle.cs b/Boolean.CSharp.Main/Misc/Unicycle.cs
index 461cb23..b0f4fac 100644
--- a/Boolean.CSharp.Main/Misc/Unicycle.cs
+++ b/Boolean.CSharp.Main/Misc/Unicycle.cs
@@ -12,5 +12,10 @@ public class Unicycle
 
         public string NameOfUnicyclist { get => _nameOfUnicyclist; set => _nameOfUnicyclist = value; }
         public int WheelCount { get; set; } = 1;
+
+        public Unicycle(string nameOfUnicyclist)
+        {
+            this.NameOfUnicyclist = nameOfUnicyclist;
+        }
     }
 }