using System;

​

namespace CoinBoxProbability

{

    enum Coin

    {

        Gold,

        Silver

    }

    class Box {

        public Coin First { get; private set; }

        public Coin Second { get; private set; }

        public Box(Coin first, Coin second)

        {

            First = first;

            Second = second;

        }

​

        public Tuple<Coin, Coin> PickCoins() =>

            Program.Random.Next(2) == 0 

                ? Tuple.Create(First, Second)

                : Tuple.Create(Second, First);

    }

​

    class BoxSet

    {

        public Box[] Boxes { get; private set; } =

        {

            new Box(Coin.Gold, Coin.Gold),

            new Box(Coin.Gold, Coin.Silver),

            new Box(Coin.Silver, Coin.Silver),

        };

​

        public Box PickBox() => Boxes[Program.Random.Next(Boxes.Length)];

    }

​

    class Program

    {

        public static Random Random = new Random();

        public const int IterationsCount = 10000;

        static void Main(string[] args)

        {

            var set = new BoxSet();

            int silverCount = 0, goldCount = 0;

            for (var i = 0; i < IterationsCount; i++)

            {

                var (firstCoin, secondCoin) = set.PickBox().PickCoins();

                if (firstCoin != Coin.Gold)

                    continue; // Не наш случай - первая вытащенная монета должна быть золотой

                if (secondCoin == Coin.Gold)

                    goldCount++;

                else

                    silverCount++;

            }

​

            var totalCases = silverCount + goldCount;

            Console.WriteLine($"Общее количество итераций: {IterationsCount}, первая вытащенная монета золотая в {totalCases} случаях ({(double)totalCases / IterationsCount:P})");

            Console.WriteLine($"Вторая монета золотая в {goldCount} случаях ({(double)goldCount/totalCases:P} от {totalCases})");

        }

    }

}