First, do 40 - 12 = 28 (Subtract the change), then do 28 / 7 to get 4, so then we do the cans times 3 to see how many individual balls he has, which would be 12
Well you would subtract 0.4 by 0.3 and get 0.1. So 0.1 is your answer
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
