using System;

public class Program

{

    public static void Main()

    {

        Random rnd = new Random();

        const double critMult = 5;

        double dmg = 100;

        double critChance = 10 / 100.0f;

        double totalDmg = 0;

        const int iterations = 1000000;

        for( int i=0; i<iterations; i++ ) {

            double d = dmg;

            if( rnd.NextDouble() <= critChance ) d *= critMult;

            totalDmg += d;

        }

        Console.WriteLine( "Avg dmg: " + (totalDmg / iterations) );

        //Console.WriteLine( "Avg dmg from formula: " + () (dmg + (dmg * (critChance) * critMult - dmg)) );

        Console.WriteLine( "Avg dmg from formula: " + (dmg * ( (1 - critChance) + critChance * critMult)) );

    }

}