Forge/Hoard Probability

#!/usr/bin/env ruby

class Card
    attr_reader :name

    def initialize(name)
        @name = name
    end

    def to_s()
        "<Card #{@name}>"
    end
end

class Deck
    def initialize()
        @cards = Array.new
    end

    def add(card)
        @cards << card
    end

    def draw_random_five()
        return @cards.shuffle()[0..4]
    end
end

myDeck = Deck.new()
3.times { myDeck.add(Card.new("Forge")) }
3.times { myDeck.add(Card.new("Duchy")) }
3.times { myDeck.add(Card.new("Gold")) }
6.times { myDeck.add(Card.new("Other")) }

matches = 0
iterations = 1000000
iterations.times do
    hand = myDeck.draw_random_five()
    num_forge = hand.count { |c| c.name == "Forge" }
    num_duchy = hand.count { |c| c.name == "Duchy" }
    num_gold = hand.count { |c| c.name == "Gold" }
    matches += 1 if num_forge>0 and num_duchy>0 and num_gold>0
end
puts "#{100*matches.to_f/iterations.to_f}%"