Three guys go into a hotel wanting to rent a room.
The owner tells them he has 1 room available and will rent it to them for $30.00 a night.
"Ten Dollars Each" Right?

Later in the day, The owner realizes that he overcharged them. He gives the bellboy "Five Dollars" and tell him to give it to the guys in room 810

On the way up the elevator, The bellboy decides that there is no way to split 5 dollars equally amoung 3 people. So he keeps "Two Dollars" and then, he gives them each a dollar back.
So, They each paid "Nine Dollars for the room Right?

3 X 9 = 27 and the 2 the bellboy kept = 29

Where did the other dollar go?