This depends how much it costs per load of laundry.
For example:
If 1 load of laundry costs $2.50, this would mean that you need 10 quarters for one load. Multiply that by 10, and you get 100 quarters (the equivalent of $25).
Depending on how much the load costs, simply divide the price per load by .25 to get you total in quarters, then multiply it by 10 in this case.