Deal or no Deal

dealornodeal.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace DonD
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] boxes = new[] { "1p", "10p", "50p", "£1", "£5", "£10", "£50", "£100", "£250", "£500", "£750", "£1,000", "£3,000", "£5,000", "£10,000", "£15,000", "£20,000", "£35,000", "£50,000", "£75,000", "£100,000", "£250,000" };
            string targetBox = "£250,000";

            int sets = 3;
            int tries = 10000;
            
            var rand = new Random();

            for (var s = 0; s < sets; s++)
            {
                int rtl = 0;
                int random = 0;

                for (var i = 0; i < tries; i++)
                {
                    List<string> randomBoxes = new List<string>(boxes.OrderBy(x => rand.Next()));

                    // Going right-to-left
                    if (randomBoxes.Last() == targetBox)
                        rtl++;

                    // Picking at random
                    while (randomBoxes.Count > 1)
                    {
                        var index = rand.Next(0, randomBoxes.Count);
                        randomBoxes.RemoveAt(index);
                    }

                    if (randomBoxes.ElementAt(0) == targetBox)
                        random++;
                }
                Console.WriteLine(string.Format("After {2} tries: RTL = {0}, Random = {1}", rtl, random, tries));
            }

            Console.ReadKey();
        }
    }
}