Mariel has $ 5.75 in dimes and nickles in her car. The number of nickles is seven more than the number of dimes.

Question

Mariel has $5.75 in dimes and nickles in her car. The number of nickles is seven more than the number of dimes. How many of each type of coin does she have?

Answer 1

N=7+D

N-D=7

5N-5D =35

.05N+.10D=5.75

5N+10D =575

5(7+D)+10D= 35+5D +10D= 15D+35= 575

15D = 575-35 = 540

D= 540/15 = 36 Dimes

N= 43 Nickels

5(43) +10(36) = 215+360= 575