Three tourists checked in at a hotel one night for $30, which they divide by paying $10 each. That night, the desk clerk realized he made a mistake, so the night really only cost $25. He sends a bellboy to return $5 to the three men, but the bellboy decided to only give $1 to each man and keep $2 for himself. Overall, each man ended up paying $9 for a total of $27, plus $2 for the bellboy. That's $29. Where did the missing dollar go?
Hint: There's nothing tricky with the numbers themselves, but be careful not to add where you should subtract or subtract where you should add.
Solution: The cost of the rooms were $25, plus $2 for the bellboy for a total of $27. There was no missing dollar, and the $29 is a result of unnecessary adding.