static void Main() { Animal[] animals = new Animal[4]; animals[0] = new Cat("Tom", 10, "Mujko"); animals[1] = new Dog("Sparky", 5, "Mujko"); animals[2] = new Frog("Gufi", 3, "Mujko"); animals[3] = new Kitten("Liza", 6, "Jensko"); double averageAge = animals.Average(animal => animal.Age); Console.WriteLine(averageAge); }