Talk about Spreadshirt (2009-11-24, 10:02:58):
no clue why i'm still up b/c clearly the rest of twitter is asleep.. see u in 4 hrs. :-) http://its-rudewear.spreadshirt.com/
Adam the t-shirt salesman has three business cards: a black card that is black on both sides, a white card that is white on both sides and a mixed card that is black on one side and white on the other. He pulls one from his pocket at random and hands it to you. The side facing you is black. What is the probability that the reverse side is also black?
American Apparel classic T-Shirt, 100% cotton 
American Apparel classic T-Shirt, 100% cotton 
American Apparel classic T-Shirt, 100% cotton 
Ami
Dave
Legal Information | Jobs | About Us | Press
Since you already know that one of the sides is black.. the white|white card is discarted, leaving you with to cards (black|black, black|white).. so i would say 50% chance?
hrmmm, phrasing of the question here is very important, could be 2/3 or 66.67%
Any other guesses?
i think it should be 2/3. There are three black sides. keep in mind it could be all three of those. You could either have the black side of the black/white card in your hand, or either of the black sides of the black/black card. So p should be 66.6% in my opinion.
is this the famous monty hall problem and it’s actually 2/3?
As Emigdio say, since you already know that one of the sides is black, the white|white card is discarted, leaving you with only two cards. Just one of them may by black on the reverse side too, then the probability is 50%.