using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace ConsoleApplication10 { class Program { static int num; static long factorial = 1; static void facto() { Console.WriteLine("Enter the number limit should be less than 20"); num = Convert.ToInt16(Console.ReadLine()); if (num > 20) { Console.WriteLine("You exceed the limit "); } else { if (num < 0) ...