I found this interesting puzzle called the Monty Hall Puzzle.
You are the contestant on a Game Show. There are 3 doors – say A,B and C – and behind one door is the prize of a million dollars. The prize is randomly placed and the probability of finding the prize behind any door is 1/3.
You get to pick one door and if you’ve picked the right door, you win the prize.
There’s a catch. After you’ve chosen a door, the game show host will not immediately open that particular door. The host will open another door that you did not pick and which he knows does not contain the prize. Supp