3 guys pay $30 for a 1 night stay at a hotel. The cost of a 1 night stay was really $25, so the receptionist gives $5 to another employee to give back to the 3 men. The employee didn't know how to split the $5 three ways, so he gives $3 back the the guys, $1 each, and keeps the remaining $2.
Since the guys initially payed $10 each for the room, $30 total, and got back $1 each, they really only payed $9 each. (Now the hard part...) Since they each payed $9 each, $27 total (9x3), and the employee kept $2, what happened to the other dollar?