Folks,
Marilyn Vos Savant reputedly has the highest IQ ever recorded. She publishes a weekly column in Parade, "AskMarilyn." This Sunday (26 November 2006)she posted the following question and answer:
Q:
You are on a game show with three doors. A car is behind one; goats are behind the others. You pick door No. 9. Suddenly, a worried look flashes across the host's usually smiling face. He forgot which door hides the car! So he says a little prayer and opens No. 3. Much to his relief, a goat is revealed. He asks, "Do you want door No. 2?" is it to your advantage to switch?
W.R. Neuman, Ann Arbor, Mich.
A:
Nope. If the host is clueless, it makes no difference whether you stay or switch. If he knows, switch.
Is Marilyn correct? If not why not?
Cheers,
Dr. Ron