A dealer offers to you to play a game. He shows you three two-sided cards: one with both sides red, one red and black and the other black and black. He puts them in a hat, and randomly (no tricks here) takes out a card and puts it on the table.

You both see only one side of the card. At this point he says that if the bottom side is the same as the top, he will take your money. If the other side is different, you double it. He explains that by now one of the cards is ruled out - if you're seeing red, the card cannot be a double black card, and vise versa - so you have a 50/50 chance of winning.

Is this a fair game? Why or why not?

(In reply to re(2): Simply stated (solution) by TomM)

I agree with you... I merely posted the example in which the odds would not nessecarily be 1:2, depending on the card's face that was showing.

In my example, I believe your the "fair" price to play the game cnagnes depending on when you have to put your money down. In the original problem, that is not the case - there is only the illusion of an increased chance of winning.

Posted by levik on 2002-07-16 08:40:34