Monday, September 27, 2010

Life of Death - One puzzle a day - Puzzle Buddies

You are a prisoner sentenced to death. The King offers you a chance to live by playing a simple game. He gives you 50 black marbles, 50 white marbles and 2 empty bowls. He then says, "Divide these 100 marbles into these 2 bowls. You can divide them any way you like as long as you use all the marbles. Then I will blindfold you and mix the bowls around. You then can choose one bowl and remove ONE marble. If the marble is WHITE you will live, but if the marble is BLACK... you will die."

How do you divide the marbles up so that you have the greatest probability of choosing a WHITE marble?
Solution: Place 1 white marble in one bowl, and place the rest of the marbles in the other bowl (49 whites, and 50 blacks). This way you begin with a 50/50 chance of choosing the bowl with just one white marble, therefore life!
Vinay is the winner!

1 comment:

  1. first bowl contains -1 white marble
    second bowl contains-49 white marbles,50 black marbles

    Probability of finding a white marble=1/2+(1/2*49/99)=0.75(Approx)

    ReplyDelete