Monty Hall Problem: The probability puzzle that makes your head melt

Dr John Moriarty, senior lecturer in probability and statistics.

Dr John Moriarty, senior lecturer in probability and statistics, explains one of the subjects most confusing teasers to the BBC, and offers up another.

First published in American Statistician in 1975, the question suggests a TV show in which contestants choose from one of three closed doors and win whatever is behind it. One door conceals a Cadillac, behind the other two are goats. The game show host knows where the Cadillac is and opens one of the doors not chosen. You are duly greeted by a goat, and then offered the chance to switch your choice to the other remaining door.

Most people will think that with  two choices remaining and one Cadillac, the chances are 50-50.

If you would like to find out why this may not be the case, and to further test your problem solving skills with another brain-teaser, you can read the full article on the BBC website.

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