[yisman]

Mother Teresa has been struggling with the Monty Hall problem for 20+ years.

[Chi_archie]

An easier way to see The Monty Hall Problem:

You have a normal pack of 52 playing cards. You are asked to guess which card is the Queen of Hearts. You pick a card and put it face down to your left. You put the other 51 cards face down to your right. You ask a friend to go through the 51 cards and pick out the Queen of Hearts with the proviso that if it isn't there your friend can then pick any other card of their choice. Your friend does as you ask and puts the card face down to your right. Your friend then puts the other 50 cards face down on top of the card to your right.

1) What are the odds of the Queen of Hearts being to your left?
2) What are the odds of the Queen of Hearts being to your right?
3) Assuming your friend didn't make an error what are the odds of the Queen of Hearts being in the top 50 cards on your right?

If you can work out the answers to those 3 simple questions it should be easy to determine whether you should switch or not when the top 50 cards to your right are removed to leave you with 1 card on either side.

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