The sign states:
1) Copies cost 10 cents each
2) Copy machines only take quarters
3) Copy machines do not make change. If you make 1 copy, you don't get 15 cents back.
The least number of copies Al can make without losing money is 5.
5 x 10 cents = 50 cents
50 / 0.25 = 2
Al can insert two quarters in the copy machine and have 5 copies. He can have an interval of 5 copies to get his money's worth.
