Riddle Me This

Three brother check into a hotel and rent one room. The clerk tells them the room is $30. for the night, so each brother contributes $10 and the room is paid in advance.About an hour after check-in the clerk discovers that he charged the weekend rate of $30 instead of the weekday rate of $25.

The clerk gives the bellhop $5 (five one-dollar bills) to return to the brothers. On the way up to the room, the bellhop realizes that they can't divide 5 dollars evenly among three brothers, so he presents only a $3 refund to their $30 hotel room, and pockets the extra $2.

Now: Each brother has paid $10 and received a $1 refund. So they spent $9 (10-1) each on the room, or $27 (3x9) total, and the Bellhop kept $2 for a total of: $29!What happened to the extra dollar?