Suppose you’re on a game show, and you’re given the 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.
They then say to you, “Do you want to pick door No. 2?”
Should you switch or not (assuming you want a car)?
The Monty Hall Problem is quite a famous one, and many of you may have seen it before. You might be able to get the right answer instinctively or by simpler methods but there is also a more maths-heavy way to solve it by using Bayes Theorem. This is particularly relevant at the moment in discussions about COVID testing – see the Guardian’s article for example. By thinking about this problem you can gain insight into contradictory seeming issues in the wider world – by having a better understanding of statistics.