Answer :
Usually these problems state the NUMBER of total coins.
4D + N = 3.60
Anyway, with trial and error I found
32 dimes and 8 nickels
32*.10 = $3.20 dimes
8 * .05 = $ .40 nickels
4D + N = 3.60
Anyway, with trial and error I found
32 dimes and 8 nickels
32*.10 = $3.20 dimes
8 * .05 = $ .40 nickels