17 possible combinations
1. 3 quarters
2. 2 quarters, 1 dime, 1 nickel
3. 2 quarters, 3 nickels
4. 1 quarter, 5 dimes
5. 1 quarter, 4 dimes, 2 nickels
6. 1 quarter, 3 dimes, 4 nickels
7. 1 quarter, 2 dimes, 6 nickels
8. 1 quarter, 1 dime, 8 nickels
9. 1 quarter, 10 nickels
10. 7 dimes, 1 nickel
11. 6 dimes, 3 nickels
12. 5 dimes, 5 nickels
13. 4 dimes, 7 nickels
14. 3 dimes, 9 nickels
15. 2 dimes, 11 nickels
16. 1 dime, 13 nickels
17. 15 nickels