Let d be dimes and q be quarters. Set up two equations from our givens:

- d + q = 41
- 0.1d + 0.25q = 7.85

__Rearrange (1) by subtracting q from each side:__

(3) d = 41 - q

__Now, substitute (3) into (2)__

0.1(41 - q) + 0.25q = 7.85

4.1 - 0.1q + 0.25q = 7.85

__Combine q terms__

0.15q + 4.1 = 7.85

__Using our equation calculator, we get:__

**q = 25**

__Substitute q = 25 into (3)__

d = 41 - 25

**d = 16**