Question

Gi finds some dimes and quarters in her backpack. There are 5 fewer quarters than dimes. The total value of the coins is $1.20. How many of each coin does Gi find?

Answer 1

0.25q + 0.10d = 1.20
q = d - 5

0.25(d - 5) + 0.10d = 1.20
0.25d - 1.25 + 0.10d = 1.20
0.25d + 0.10d = 1.20 + 1.25
0.35d = 2.45
d = 2.45 / 0.35
d = 7 <=== there are 7 dimes

q = d - 5
q = 7 - 5
q = 2  <==== there are 2 quarters