You are about to be executed, but the king gives you a chance. He says that he will divide 100 marbles in half. 50 of them are black and 50 are white. You can arrange them however you like into two bowls, but you must use all the marbles. The king will then blindfold you and switch them around. Then you choose a single marble from whichever bowl you put your hand randomly in. If you choose a white marble you can live, but if you choose a black one you die. How do you divide the marbles so there is a 50-50 chance you will live?
You need to put one white marble in one of the bowls. Then the remaining 49 go with the 50 black marbles. Then you will have a good chance of living.