From the Exploring Data website - http://curriculum.qed.qld.gov.au/kla/eda/
© Education Queensland, 1997

Three Men and a Bellboy

This has nothing to do with probability, but it is a great puzzle.....

Three men go to a hotel. They ask the clerk, "How much is a room?" and the clerk tells them it is $30. They each pay the clerk $10 and go to the room. The clerk knew that the room rate was really only $25 and started to feel guilty about overcharging the men so he gave the bellboy a $5 bill and told him to return the money to the men.

The bellboy knew that $5 didn't divide evenly among the three men, so he kept the $5 bill and returned one dollar to each of the men, keeping the extra $2 for himself.

So each of the three men paid $9 for the room ($27 total) and the bellboy kept $2. Where is the other dollar?