Three friends buy a gift for a fourth friend. The gift is $30.00. Each of them pays $10.00. The next day the manager decides he charged them too much. He gives his assistant $5.00 to return to them. The assistant pockets $2.00 and gives the friends back $3.00. Now each of them paid $9.00 a piece which equals to $27.00 plus the assistant has $2.00. That equals $29.00 where is the other dollar?