Question 1016476
30 cents in nickels is 6 coins. 

The problem reduces to 56 coins, $10.85 in dimes and quarters. 

10D+25Q= 1085

D+Q=56  (multiply by 10)

10D+10Q=560

15Q= 525

Q=35

D = 21

Check, 35 quarters are $8.75
21 dimes is $2.10

Adds to $10.85

And remember 6 nickels.