static void Main(string[] args) { Dog sharo = new Dog("Sharo", 2, Gender.Male); Dog mecho = new Dog("Mecho", 3, Gender.Male); Dog tara = new Dog("Tara", 1, Gender.Female); Frog froggy = new Frog("Froggy", 5, Gender.Male); Frog kiki = new Frog("Kiki", 2, Gender.Female); Cat daisy = new Cat("Daisy", 3, Gender.Female); Cat harry = new Cat("Harry", 4, Gender.Male); Kitten kitty = new Kitten("Kitty", 1); Tomcat tommy = new Tomcat("Tommy", 2); Animal[] animals = new Animal[] { sharo, mecho, tara, froggy, kiki, daisy, harry, kitty, tommy, }; double averageAgeOfDogs = animals.Where(animal => animal is Dog).Average(animal => animal.Age); double averageAgeOfFrogs = animals.Where(animal => animal is Frog).Average(animal => animal.Age); double averageAgeOfCats = animals.Where(animal => animal is Cat).Average(animal => animal.Age); double averageAgeOfKittens = animals.Where(animal => animal is Kitten).Average(animal => animal.Age); double averageAgeOfTomcats = animals.Where(animal => animal is Tomcat).Average(animal => animal.Age); Console.WriteLine("Average age of dogs: {0} \nAverage age of frogs: {1}" + "\nAverage age of cats: {2} \nAverage age of kittens: {3} \nAverage age of tomcats: {4}", averageAgeOfDogs, averageAgeOfFrogs, averageAgeOfCats, averageAgeOfKittens, averageAgeOfTomcats); }