On Wednesday, 8 October 2014 at 07:00:38 UTC, Dominikus Dittes
Scherkl wrote:
On Wednesday, 8 October 2014 at 01:22:49 UTC, Timon Gehr wrote:
It doesn't matter if he uses his knowledge to open always a
false door.
It does. Actually, this is the single most important thing.
It only matters that you open your door AFTER him,
which allows you to react on the result of his door. If you
open the door first, your chance is only 1/3.
If his choice would be completely random, as you seem to suggest
above (because, actually, its choice is conditioned by your first
choice) then, even if you open a door after him, the only thing
you have is the fact that you are now in problem with 50%
probability to win.
If you remove the above piece of information, you could simply
assume that there are only two doors and you are to open one of
them. In this case is just 50/50.
