If you're ever on game show with, say, a GTI as a prize, you may want to know about this . . .

Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a GTI; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, "Do you want to switch from door No. 1 to door No. 2?" Is it to your advantage to switch your choice?

As the player cannot be certain which of the two remaining unopened doors is the winning door, most people assume that each of these doors has an equal probability and conclude that switching does not matter.

In fact, all things being equal, the player should switch—doing so doubles the probability of winning the car, from 1/3 to 2/3.

Worth knowing if you ever find yourself in the enviable position of being in the running to win a car!