static void Main() { var dogs = new Dogs[] { new Dogs("Rex", 7, Sex.Male), new Dogs("Sharo", 11, Sex.Male), new Dogs("Sara", 15, Sex.Famale) }; var frogs = new Frogs[] { new Frogs("Crazy Frog", 3, Sex.Male), new Frogs("Pesho", 5, Sex.Male), new Frogs("Jabka", 2, Sex.Famale) }; var cats = new Cats[] { new Tomcats("Tom", 5), new Kittens("Kitty", 4), new Cats("Kotan", 6, Sex.Male) }; var averageAgeOfDogs = dogs.Average(d => d.Age); var averageAgeOfFrogs = frogs.Average(f => f.Age); var averageAgeOfCats = cats.Average(c => c.Age); Console.WriteLine("Avarage age of dogs: {0:F1}", averageAgeOfCats); Console.WriteLine("Avarage age of frogs: {0:F1}", averageAgeOfFrogs); Console.WriteLine("Avarage age of cats: {0:F1}", averageAgeOfCats); }