Three friends go out for a hunting trip. After they had been out all day, and it was beginning to get dark the three stumbled upon a hunting lodge. Amongst themselves they agree to get a room for the night.

Once entering the establishment the three approached the receptionist and ask for a room for the night.

The receptionist replies, "A room is thirty dollars for the night"

Between the three friends they agree to stay the night and each pay an equal share of ten dollars.

A few moments later the receptionist realizes she made a mistake and the Inn is having a special. A room is only Twenty five dollars for the night. She hands the bag-boy five dollars in one dollar denominations, instructing him to refund the three friends that had just checked in.

On his way up the stairs the bag-boy ponders his dilemma. He has five one dollar bills and only three individuals in which to divide it amongst. Thinking quickly he decides to keep two dollars as a tip for himself and give each of the three guys a dollar back.

So the question; If the three friends each received a refund of $1 after paying $10 each, then they paid $9 each for the room. So, between the three friends 9x3=$27. So..., 27 plus 2(that the bag-boy kept) equals $29, and they originally paid $30. Where did the other dollar go?