using System;

using System.Collections.Generic;

using System.Linq;                  

public class Program

{

    public static void Main()

    {

    List<double> radius = new List<double> { 10, 20, 30, 40, 50 };

    double average = radius.Average();

    double sum = radius.Sum();

    Console.WriteLine("The average radius is {0}.", average);

    Console.WriteLine("The sum of radius is {0}.", sum);

    }

}