Heh, thats like the cheaters way of proving it. You basically said, well, you spent $30, the bellhop took $2, so $30-$2=$28, and he gave you back $3, so $28-$3=$25...

You just restated the problem. The question is saying, that if the bellhop took $2, and you each received $1 back, you in essence paid $9 per person, plus the $2 taken, which is $29. Why did this happen is what the riddle is asking...