Three men go into a motel.
The desk clerk said the room was $30, so each man paid $10 and went to the room.

A while later, the desk clerk realized the room was only $25, so he sent the bellboy to the three guys' room with $5.
On the way, the bellboy couldn't figure out how to split $5 evenly between three men, so he gave each man $1 and kept the other $2 for himself.

This meant  that the 3 men each paid $9 for the room, which is a total of $27.

Add to that the $2 the bellboy kept and the total is $29. Where is the other dollar?