Originally Posted by Analise
Unless your waiter did an absymal job, I am not sure why you think a 5% tip is appropriate. Clearly the waiter wasn't too bright to give you change like that so you just ask him to break the 20s in the denominations you want. Then tip based on his level of service to you.
I think the OP's point is that he/she shouldn't have to make a second request for the "correct" change by breaking a twenty. My guess is that the OP realizes that a 5% tip is probably grossly inadequate, but if the waiter/waitress can't think through the fact that bringing back two twenties and three singles is just begging the question "will you please break a $20?", then maybe 5% is appropriate.
I have to say, this is one of my dining pet peeves. The "correct" change was one twenty, two tens, and three ones. In fact, as
TRRed said, I think that the two tens should really be one ten and two fives, just to cover all the bases.