A jar of dimes and quarters contains $15.25. There are 103 coins in all. How many quarters are in the jar?

1 Answer

This is a problem that will use two equations.

D= " number of dimes and " Q = " number of quarters"

There are 70 " dimes " and 33 " quarters"

Explanation:

0.1D+0.25Q=15.25

(This is because a dime is worth $0.10 and a quarter is worth $0.25.)

D+Q=103 " "rarrD=103-Q

Substitute D into the first equation.

0.1(103-Q)+0.25Q=15.25

10.3-0.1Q+0.25Q=15.25

0.15Q=4.95

Q=33

Substitute for Q into the second equation.
D+33=103

D=70

FINAL ANSWER:

There are 70 " dimes " and 33 " quarters"