<< What book or magazine article or website has the best (in your opinion) written explanation of the Monty Hall Paradox for the lay reader?
Question: --------- Behind one of three doors - A, B, and C -- is a car; behind each of the other two is a goat. The player, P, gets to keep what's behind the door he chooses to open. First P picks one door that remains closed at first, say door A. Now one of the other doors is opened to show a goat -- say door B -- and P gets to make their final choice: open the original choice of door A, or the other door -- call it C -- that's still closed. Which is more likely to get the car? ------------------------------------ Answer: ------- The player should pick door C for the best chance of getting the car. Explanation: ------------ Player P has 1/3 chance of guessing the car with their original choice of door A. Showing the goat sheds no light on whether the initial choice of door A is correct, so its probability remains 1/3. Hence the probability the car is not behind door A must be 2/3. Since door B has been excluded from hiding the car, that 2/3 probability belongs to door C. QED --Dan _____________________________________________________________________ "It don't mean a thing if it ain't got that certain je ne sais quoi." --Peter Schickele