Pick a box, you have 1/3 chance of getting the car 2/3 of not getting it.
They then eliminate 1 of the options so, you have a 1/3 chance of your box being right and a 2/3 of the other being right.
(PsychoChomp, Wed 20 Jun 2012, 15:59, 1 reply, 13 years ago)

I can't see how the original choice is relevant

( Naked Ape call me Caitlyn, Wed 20 Jun 2012, 16:00, Reply)

Imagine you pick box 1
That means you don't pick box 2 or 3, think about 2&3 as "not box 1"
An incorrect box say 2 is then removed.
So your choice is box 1 or box 3, but it's better to think about it as box 1 or "not box 1" which givs you the 1/3rd chance of it being box 1 and a 2/3rd chance of being "not box 1" which is box 3
(PsychoChomp, Wed 20 Jun 2012, 16:05, Reply)

Or think of it as box 1 or 3
and your have a 50/50 chance
( Naked Ape call me Caitlyn, Wed 20 Jun 2012, 16:07, Reply)

Well you can think of it like that but you'll be wrong.

(PsychoChomp, Wed 20 Jun 2012, 16:07, Reply)

i can se the logic to your solution
however it feels like clever maths rather than actual real world fact
( Naked Ape call me Caitlyn, Wed 20 Jun 2012, 16:11, Reply)

It's a real world fact that has been proven by repeately opening boxes.

(PsychoChomp, Wed 20 Jun 2012, 16:12, Reply)

I AGREE WITH CHOMPY

( Peej, Wed 20 Jun 2012, 16:21, Reply)

no, statistically it's entirely correct
the problem is that it only works if you assume that the questionmaster didn't know there would be goats behind door 2. Once you accept that if it were a real world problem there would be knowledge on the part of the questionmaster then the odds are meaningless
( the mighty badger Aphrodite, on a bar stool, by your side, Wed 20 Jun 2012, 16:24, Reply)

It works because at the point you chose your box you had a 2/3 chance of being wrong
when they remove one of the wrong boxes you still have the same chance of being wrong but because they have removed an incorrect box you have a 2/3 chance that the other box is right.

You see?
( Peej, Wed 20 Jun 2012, 16:26, Reply)