The Monty Hall Problem: There's A Right Answer But Even Genius Math Geeks Get It Wrong

The Monty Hall Problem is a famous probability problem named for the original host of "Let's Make A Deal." The controversy began in 1990 when Marilyn von Savant posed the question in her column.

The Monty Hall Problem: A contestant on a game show is asked to choose between three doors, behind one of which is a brand new car. Then the host, who knows where the car is hidden, opens one of the other doors where there is no car. The host then asks the contestant if they would like to stay with their original door or switch to the other unopened door. Should the contestant stay or switch?

Marilyn von Savant said that the contestant should always switch doors to increase their odds of winning. This counterintuitive solution created a massive debate. Von Savant received about 10,000 letters from readers, including many PhDs, telling her she was mistaken. But she was right. Contestants that switch doors increase their chances of winning from 1/3 to 2/3. See the step-by-step explanation in the video.