You and two friends go to a hotel to spend the night, it costs $30 so you decide to split it evenly three ways and each pay $10. However after you have paid and gone to your room the clerk realized that all rooms were $5 off, so he tells a bell hop to take the $5 dollars to your room. He decides to take $2 as payment for having to go to your room and gives each of you a dollar back so you each paid $9 dollars for the room. But one dollar is missing, because if you each paid $9 dollars then that's $27 and the $2 the bell hop has makes $29, where is the missing dollar?
Yes i know it's a riddle and not technically a philosophical question but i want to see if you can get it, and no googling/yahooing/ asking random person for the answer!