its puzzle time

three ladies walk into a restaurant. after their meal, they each put down 10 dollars. (that totals 30 dollars.) the waiter takes the money, and finds out the bill is only 25 dollars. He returns with 5 one dollar bills, but he knows that the ladies don't know what the total bill is and that he can't split 5 dollars evenly between the three of them, so he pockets 2 dollars, and returns 1 dollar to each of the ladies.

therefore, each lady paid 9 dollars. that's a total of 27 dollars. the waiter took 2 dollars. where did the extra dollar go?