[Pauwl]

Together they spend $25 on the room. So each guy spends 25/3 = 8.33$ on the room. They got $1 change each and together left a tip of 2$.

Adding all the money you get (3 x $8.33) + (3 x $1) + 2$ = $30

In the question, they only account for the boys' 9$ a piece on the room, but that's incomplete, they actually spent $8.33 each on the room and each got $1 back. So the equation in the question should have been (3 x (8.33 + 1)) + $2 tip = $30. So the answer to the question is that the other $1 goes to the guys having homosexual sex in the room [img]/images/graemlins/grin.gif[/img].

edit:grammar