Question

A class contributed $18.50 in quarters and dimes to a fundraiser. In all, there were 80 coins. How many of each coin were there?

a) 40 quarters and 40 dimes
b) 50 quarters and 30 dimes
c) 60 quarters and 20 dimes
d) 70 quarters and 10 dimes

Answer 1

There are 70 quarters and 10 dimes in the contribution. The correct answer is option d) 70 quarters and 10 dimes.

Step-by-step explanation:

Let's assume the number of quarters is represented by q and the number of dimes is represented by d. We can set up a system of equations to solve for q and d:

q + d = 80 (equation 1)

0.25q + 0.1d = 18.50 (equation 2)

To solve this system, we can use substitution or elimination method. Let's use substitution method. Solve equation 1 for q: q = 80 - d. Substitute this value into equation 2:

0.25(80 - d) + 0.1d = 18.50

20 - 0.25d + 0.1d = 18.50

20 - 0.15d = 18.50

-0.15d = -1.5

d = 10

Substitute this value into equation 1 to solve for q:

q + 10 = 80

q = 70

Therefore, there are 70 quarters and 10 dimes. The correct answer is option d) 70 quarters and 10 dimes.