3 men go into a motel. The man behind the desk said the room is $30, so each man paid $10 and went to the room.*
A while later the man behind the desk realized the room was only $25, so he sent the bellboy to the 3 guys' room with $5. On the way the bellboy couldn't figure out how to split $5 evenly between 3 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 the $2 that the bellboy kept = $29.
Where is the other dollar?
*Don't ask why 3 men are sharing one room. That's irrelevant to the challenge.