where the heck is that dollar?

A couple nights ago I was at Starbucks w/ a bunch of friends. We were having fun just talking and hanging out .... when we started to do riddles. It was mostly those crazy ones where you can ask yes or no questions, until Aaron pulled out a math one. It really bugged me ..... I had to solve it ... which I of course finally did (or I would not be doing this post lol). Anyways ... I couldn't find it on the internet ... but this one is VERY similar. You solve it the exact same way. ENJOY ;)

Three friends check into a motel for the night and the clerk tells them the bill is $30, payable in advance. So, they each pay the clerk $10 and go to their room. A few minutes later, the clerk realizes he has made an error and overcharged the trio by $5. He asks the bellhop to return $5 to the 3 friends who had just checked in. The bellhop sees this as an opportunity to make $2 as he reasons that the three friends would have a tough time dividing $5 evenly among them; so he decides to tell them that the clerk made a mistake of only $3, giving a dollar back to each of the friends. He pockets the leftover $2 and goes home for the day! Now, each of the three friends gets a dollar back, thus they each paid $9 for the room which is a total of $27 for the night. We know the bellhop pocketed $2 and adding that to the $27, you get $29, not $30 which was originally spent. Where did the other dollar go????