Suppose you’re on a game show, and you’re given the choice of three doors: Behind one door is a car; behind the other 2, 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?” In other words and the question you have to answer – is it to your advantage to switch your choice?
This is The Monty Hall problem – a brain-teaser in the form of a probability puzzle. Have a go at it yourself, or if you’re having trouble you can find the solution here.
We often have trouble deciding whether to change our minds in real life too. Especially when we have invested a lot in our original decision.
Sometimes however, we must give up on the original plan and realise it makes more sense to switch.