Janet has three times as many dimes as nickels and twice as many quarters as nickels. If she has $3.40 in all, how many nickels, dimes, and quarters does she have? If n represents the number of nickels Janet has, which of the following equations could be used to solve the problem?
A) 5n + 10n + 25n = 340
B) n + 3n + 2n = 340
C) 5n + 30n + 50n = 340