Originally Posted by Hotdog

This one is tough to explain (unless you google it so dont!)...

Three men went into a cheap hotel, and asked for a room. The desk clerk gave them a room for 30 dollars. They each paid a ten dollar bill and went up to their room. A while later, the desk clerk realized that he had made a mistake - the room he had given them was only a 25 dollar room. He called the bell boy over, and handed him five dollar bills. "Take this up to Room 17 and give it to the men with my apologies". The bellboy figured that he had a chance to made some money here - since the men wouldn't know the difference, he just gave them back three dollars, and put two in his pocket.
So, the men had originally paid ten dollars each for the room. They each got one dollar back, which meant they paid nine dollars.
9 X 3 is 27. The bellboy kept two dollars. 27 + 2 is 29. What happened to the other dollar?