Question

Michelle has a jar of quarters and dimes totalling to 3.10 if there are sixteen coins in the jar how many more quarters are there than dimes?

Answer 1

q + d = 16....q = 16 - d
0.25q + 0.10d = 3.10

0.25(16 - d) + 0.10d = 3.10
4 - 0.25d + 0.10d = 3.10
-0.25d + 0.10d = 3.10 - 4
-0.15d = -0.90
d = -0.90/-0.15
d = 6...dimes

q + d = 16
q + 6 = 16
q = 16 - 6
q = 10...quarters

so there are (10 - 6) = 4 more quarters then dimes