How many coins of each kind?

I have 30 coins consisting of nickels and quarters. The total value of the coins is $4.10. How many of each kind do I have?

I have nickels and quarters => 5+25=30
Total value of coins = 410

The largest value divisible by 30 which is less than 410 is 13*30 = 390
Remaining value is 410-390=20 and number of coins is 13 nickels and 13 quarters.

=> 4 coins should make 20 cents i.e; 4 nickels.

So I have 17 nickels and 13 quarters.