Answer:
21 quarters and 19 dimes
Step-by-step explanation:
Create a system of equations where q is the number of quarters and d is the number of dimes.
0.25q + 0.1d = 7.15
q + d = 40
Solve by elimination by multiplying the bottom equation by -0.25
0.25q + 0.1d = 7.15
-0.25q - 0.25d = -10
Add them together and solve for d:
-0.15d = -2.85
d = 19
Then, plug in 19 as d into the second equation to solve for q:
q + d = 40
q + 19 = 40
q = 21
So, there are 21 quarters and 19 dimes
