Rob has 40 coins, all dimes and quarters, worth $7.60. How many dimes and how many quarters does he

Rob has 40 coins, all dimes and quarters, worth $7.60. How many dimes and how many quarters does he have?

We have two equations where d is the number of dimes and q is the number of quarters:

1. d + q = 40
2. 0.1d + 0.25q = 7.60

Using our simultaneous equation calculator, we get:
d = 16
q = 24