Let N = # of nickels. Then the number of dimes = (N-12), and the number of quarters = 6*(N + (N-12)) = 6*(2N-12) = 12N - 72. The the total of money equation is 5N + 10*(N-12) + 25*(12N-72) = 4380 cents. Simplify and solve for N. Then evaluate the number of dimes and the number of quarters.