Posts: 13,563
Threads: 49
Joined: Oct 2009
Okay, I figure we need a different kind of puzzle, for variety.
This one's nicked from Google, so if you've seen it before sit back and watch. If you haven't seen it before, obviously don't google for the answer.
You have a stack of 23 cards. Each card has an image of a cross on one side, and an image of a circle on the other side. You know that 14 cards in the stack are lying with the cross up, and therefore 9 cards are with the circle up. But you don't know in which order the cards are. Moreover, you are in a completely dark room, so you can't see anything.
The Question: How can you, without seeing anything, divide the stack of cards into two smaller stacks, in such a way that both stacks have the same number of cards with a cross up?
I have to run.
