wh00t's explanation, while entirely correct, didn't point out the
logical fallacy quite clearly enough for a friend of mine (
who shall remain nameless, Ian), so here it goes, for the slow ones:
The original premise:
The businessmen payed $9 a piece, for a total of $27, plus the bellhop's $2 makes $29, so where's the extra dollar?
The corrected premise:
The businessmen payed $9 a piece, for a total of $27, *minus* the bellhop's $2 makes $25, the price of the room.
Hope that clears up any remaining confusion.