There's the Dollar!

Here's the answer to the riddle proposed last week.

The men effectively paid $27 total for the room. Where is this $27? $25 of it is in the hotel's cash register, and the other $2 is in the pocket of the dishonest clerk. So it's incorrect to add the $2 that the clerk kept to the $27 that the men paid because that $2 is part of the $27. The only money that is not part of the $27 is the $3 that the men got back, and of course, $27 + $3 = $30.