Joe Orr Road Rod wrote:
leashyourkids wrote:
Jaw Breaker wrote:
Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, "Do you want to pick door No. 2?" Is it to your advantage to switch your choice?
Answer: Yes, you should always switch.
It took me years to wrap my mind around why this was true.
What is the answer? That when you originally picked your chances were 1 of 3. If you pick again your chances are 50/50. Something like that? That doesn't make practical sense though. Once the first goat is revealed, your chances are already 50/50.
The quick answer is that when you make your first pick, your odds of being right are 1/3 (and the odds of you being wrong are 2/3). So if given the choice to switch between a 1/3 chance of being right and a 2/3 chance of being right, you should always go with the 2/3 chance. The fact that the host reveals one of the other doors doesn't change the odds; however, the host will never open a door that has the prize.
Another way to look at it is instead of 3 doors, let's say there are 100. Same deal...you pick one, then the host shows one of the other 99 that does not have the prize. Now he gives you a choice: keep your one pick or switch to ALL the remaining doors (i.e., "the field"). Obviously you would switch in that case. It's the same concept, but when you do it with only three doors, it seems counterintuitive.
_________________
To IkeSouth, bigfan wrote:
Are you stoned or pissed off, or both, when you create these postings?
Login
Register
FAQ
Search
