You are a contestant on a game show. There are three curtains. Behind one of the curtains is a new car. You are asked to choose one of the curtains. Lets say that you choose curtain #1. The host of the show - who knows where the car is so as not to end the game prematurely - opens curtain #3 and of course there is no car behind it. The host now gives you a choice. You can stay with curtain #1 or you can change your choice to curtain #2. The question now is: would it be to your advantage to stay with curtain #1, or would it be to your advantage to change to curtain #2 or would there be no advantage either way?
It’s to your advantage to switch.
We’ve done this a dozen times. Search for Monty Hall.
http://boards.straightdope.com/sdmb/showthread.php?t=499621&highlight=monty+hall
Dude, that’s the Monty Hall problem and it is a very old Dope article.
Sorry - It won’t happen again.
Don’t feel bad. It’s a pretty cool demonstration of how our first reactions to math and probability related questions are occasionally exactly wrong. Explaining WHY it’s better to switch from curtain 1 to curtain 2 leaves almost everyone going, “huh?” and eventually leads to “hmm…”
I stay with my original choice.
Sure there’s a 66% chance it’s in the other curtain, but what you’re forgetting is that there’s a 100% chance that I’m awesome and have therefore picked the right curtain to begin with.