using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static Random r = new Random();

    public static void Main() 

    {

        for (var i = 0; i < 100; i++) Console.WriteLine(Generate());

    }

    private static string Generate()

    {

        var KD = new List<Tuple<double, double>>();

        for (var i = 0; i < 100; i++) {

            KD.Add(Tuple.Create((double)r.Next(1, 20), (double)r.Next(1, 20)));

        }

​

        var avgOfAvgs = KD.Select(k => k.Item1/ k.Item2).Average();

        var normAvg = (KD.Sum(k => k.Item1) / KD.Sum(k => k.Item2));

        var percentError = Math.Truncate((Math.Abs(normAvg - avgOfAvgs)) / normAvg * 100);

        return $"AOA - {avgOfAvgs} | NA - {normAvg} | PE - {percentError}%";

    }

}