Imagine you're on a game show, and you're given the choice of three doors: behind one door is a million dollars, and behind the other two, nothing. you pick door #1, and the host, who knows what's behind the doors, opens another door, say #3, and it has nothing behind it. he then says to you, "do you want to stick with your choice or switch? "

so, is it to your best advantage to stick with your original choice or switch your choice?

getty
most people think the choice doesn't matter because you have a 50/50 chance of getting the prize whether you switch or not since there are two doors left, but that's actually not true!