Deviating a little from Jokes... Brain bender time!
You are on a talk show and you have to pick among three doors, A, B, and C for the big prize. You picked A.
The Host says let me show you one door where the prize is not. He opens door C.
He then offers you the option of keeping your door or switching.
Deep inside, you know that with two choices, you have a 50/50 shot of winning the prize - or, if you rather, a 50% chance of winning.
Is this correct?
Not so fast... When you picked the door, your chance of winning was 1/3, or 33%. So, one theory is that if you keep your original door, you have a 33% chance of winning but if you chose the other door, your chance goes up to 50% as it is one of two doors.
I don't think that a previous choices' odds are fixed in stone. When the host eliminated the third door, he changed the odds for you from 33% to 50% regardless of your choice. I've been told that isn't true though. Hmm...