# Re: Math experiment

Miss Elaine Eos <Misc@xxxxxxxxxxxxxxxxxxxxxxxx> wrote in news:Misc-
8A367E.08463228052007@xxxxxxxxxxxxxxxxxxxxxxxxxxxx:

Hmmm, I think I have a bug, because I get that the guy who always
switches has a 2/3 chance of GETTING the car (not 50/50.) Here's the
crux of my logic:

* Car is behind a door: 1, 2 or 3
* Contestant picks a door: 1, 2 or 3
* Monte shows a door that is neither car-door nor picked-door (randomly
selecting, if they are the same)
* Contestant #1 always sticks
* Contestant #2 always switches to the door that is neither picked nor
shown.

Did I goof something up?

No. 2/3 is the right answer. If you stick with your first door,
you have a 1/3 change of winning. If the car is behind one of
the other TWO doors, and you switch, you're guaranteed to get it.
Monty opening that door is really a feignt. Your second choice
is between A. the best prize behind one door and B. the best
prize behind two doors.

B.

--
Cheerfully resisting change since 1959.
.

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