Author: Gerrit Reubold
Date: 07:32:18 09/27/02
Go up one level in this thread
On September 27, 2002 at 10:18:19, Uri Blass wrote: >On September 27, 2002 at 10:04:42, Gerrit Reubold wrote: > >>On September 27, 2002 at 09:45:47, Uri Blass wrote: >> >>I discuss this situation: >>- The candidate chooses door 1 >>- The host chooses (say) door 3, and is lucky, there is a goat in door 3 >> >>So there _is_ a game! >> >>Now the candidate should switch and double its winning chances. >> >>Do you agree? > >No >> >>If you don't agree: Consider the game with 1.000.000 doors, the candidate >>chooses door 1. The host opens 999.998 doors, without knowing where the car is. >>By incredible luck all those doors have goats behind them. There is now door 1 >>and door 432.102 closed. So again there is a game! Do you agree that the >>candidate should switch? > >No > >in 100000 cases you are going to have 999998 cases when there >is no game >1 case when there is a game when it is a good idea to switch and >1 case when there is a game when it is a bad idea to switch > I discuss only the situation when there is a game. The two cases when there is a game are _NOT_ equally likely. When the game starts: The car is with 999999/1000000 probability behind one of the doors 2..1000000. Do you agree? Now 999998 doors are opened, the 999999/1000000 probability is still correct. The car is with 1/1000000 behind door 1 and with 999999/1000000 behind door 432.102 Do you agree? Why should the probabilities be affected by the mind of the host, he just opens doors, with or without knowing where the car is? Greetings, Gerrit
This page took 0.03 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.