So you go to a laundromat and you go to break a $1, $5, $20 bill for quarters. Why??? because the machines only takes quarters. You spend $10 of quarters to wash and dry, for instance, at the same laundromat.......think about it for a second......
You gave them $10 bill to get quarters and you get quarters to put back in the machine at the same laundromat.......
Wow....food for thought...