using System;

​

public class Program

{

    public void Main()

    {

        double x = 1, y = 2, z = 3;

        Console.WriteLine("Average of " + x + " and " + y +" and " + z+": " + mean3(x, y,z));

        Console.WriteLine("Average of " + y + " and " + z + ": " + average(y, z));

        Console.WriteLine("Average of " + x + " and " + z + ": " + average(x, z));

    }

​

    public double average(double a, double b)

    {

        return (a + b) / 2;

    }

    public double mean3(double a, double b, double c)

    {

        return (a + b+c) / 3;

    }

}