Rose counted her money and found that her 25 coins which were nickels, dimes, and quarters were worth $3.20. the number of dimes exceeded the number of nickels by 4. how many coins of each kind did she have?

N = number of nickles

D = number of dimes = N+4

Q = number of quarters

= 25-N-D

= 25-N - (N+4)

= 21 - (2N)

Add the coins to get $3.20

(N*$0.05) + (D*$0.10) + (Q*$0.25) = $3.20

Expressing D and Q in terms of N:

(N*$0.05) + ((N+4) * $0.10) + (21-2N) * $0.25=$3.20

Solve for N. Then plug N into the equations for D and Q