Courtney has $4.95 in nickels, quarters, and dimes. she has12 quarters and 9 nickels. how many more dimes than nickels does she have? a. 15 b. 10 c. 6 d. 4

The answer to this is C. 6

You have to find the value of the coins that you have now. Then you add them. Next, you subtract that value from the original total of 4.95. After that, you take that amount and divide it by the value of a dime. Lastly, you subtract the number of nickels from the number of dimes. 
So 12x.25=3 and 9x.05=.45
3+.45=3.45
4.95-3.45=1.5
1/5/.10=15
15-9=6
The answer is 6.