math
posted by MP on .
In Ethan’s piggybank there are nickels, dimes and quarters. There are 3 times as many quarters as nickels, and 5 more dimes than nickels. How many of each kind of coins are there? Ethan has saved a total of $3.20.

Q = 3N and D = 5N
.05N + .10D + .25Q = .05N + .10(5N) + .25(3N) = 3.20
Calculate for N, then Q and D.