Riddle Time

[kthx]

I have one also.

Three guys decide to stay at a hotel while driving up to go camping somewhere, they pull in and go inside. The lady tells them the room is 30 dollars, so each person chips in 10 dollars for the room. Late that night the woman remembers there was a five dollar discount on the room and goes and gives each person 1 dollar back, and keeps two for herself because she couldn't split 5 dollars 3 ways evenly.

So if each person only paid 9 dollars after the 1 dollar discount, and the clerk kept two dollars, what happened to the last dollar?

9x3 = 27
+ 2 = 29.

[Fit of Rage]

Here's a riddle for you:

Three prisoners are sitting in jail over the winter holidays. In a gesture of good will, the warden tells them he will free them if and only if they can solve this riddle. Each of the prisoners is blindfolded. The warden brings in 5 hats: 3 are black, 2 are white. He randomly selects three hats and places them on their heads. They are unblinfolded. Each prisoner can see the hats of the other two, but not his own. In order for each prisoner to go free, they must determine the color of their own hats.

Rules:
-The prisoners are not allowed to communicate. No hand gestures, no facial expressions, no talking.
-No mirrors or reflective devices of any kind (eyes, metal surfaces). The prisoners must use logic alone to determine what color their hat is.

I suppose most people suspect that it is is possible for the prisoners to logically determine their hat color and go free no matter what the scenario. The question is, how?

If you think you have the solution, PM me. For the sake of sport, don't post the solution in the thread, even if you do give up and google it.