You're taking part in a quiz show where you're going to win either a Ferrari or a goat. You'd prefer the Ferrari. This is non-negotiable. You may be the world's greatest lover of all things goat, but in this instance you want to win the Ferrari.

You will be presented with three closed doors. Behind one door is the car, behind the other two, goats - the goats that you don't want to win. The placement of car and goats has been randomly determined. There is no trickery involved here. The host of the quiz, the eponymous Monty Hall, will ask you to choose a door. He will then open one of the two remaining doors. There are three pertinent facts here. 1) Monty knows what is behind each door. 2) He will always reveal a goat when he opens the door. 3) He has no preference for any particular goat or door.

The question you have to answer is whether or not you increase your chances of winning the Ferrari by switching your original choice to the remaining unopened door.

So to repeat:

  • There are three doors, one has a Ferrari behind it, the other two, goats.
  • You choose a door.
  • Monty, having no preference for any particular goat or door, will open one of the two doors you haven't chosen, revealing a goat.
  • This will leave two doors still closed, the door you originally chose, and the door that Monty could have chosen to open, but didn't.
  • One of these two remaining doors has a goat behind it, the other a Ferrari.
  • Will you increase your chance of winning the Ferrari if you switch from your original choice, and ask Monty to open the other door?

To make your choice, select one of the options below, then click the Submit button!