This has to be my all-time favorite brain puzzle, mainly because the answer plays with your sense of intuition, but also because of the incredible controversy it created.
The question was submitted to a famous magazine about 15 years ago, and the woman with the world’s highest recorded IQ provided the solution. Shortly thereafter, dozens of math PhD’s wrote in, blasting her for giving the wrong answer. She was, however, correct.
Here it is:
- Suppose you’re on a game show, and you’re given a choice of three doors. Behind one door is a car; 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 pick door No. 2?" Is it to your advantage to switch your choice?
Try to give it a shot on your own, and in a day or two if no one gets it right I’ll post a link to a detailed description of the answer and the story that surrounded it.