Nowhere, the question is just wrong/trying to confuse you.
Clerk charged $30, realized it was a special day, gives 5 bucks to the bell boy to bring it up to the customers. Thats $25 left. He realizes they can't split it, so he takes two bucks. Theres 3 dollars left, he gives it to the customers. Each of them get a dollar. The question ends there.
The "they payed 9 dollars each" bit is irrelevant to the question.
