Change your ConversionQuestion class to something like this:
class ConversionQuestion
{
static void Main(string[] args)
{
Doggy dog = new Doggy("Max", 3);
Human human = new Human("Leonardo", 23);
Console.WriteLine("As a Human, {0} would be {1}", DogToHuman(dog).Name, DogToHuman(dog).Age);
Console.WriteLine("As a Dog, {0} would be {1}", HumanToDog(human).Name, HumanToDog(human).Age);
Console.ReadLine();
}
public static Human DogToHuman(Doggy dog)
{
return new Human(dog.Name, (dog.Age * 7));
}
public static Doggy HumanToDog(Human human)
{
return new Doggy(human.Name, (human.Age / 7));
}
}