Sara has a jar filled with 135coins, which consists only of quarters and nickels. If sara has a total of $22.75 in the jar which of the following is the number of nickels sara has in the jar?

A. 25

B. 55

C. 80

D. 130

Answer: 80 quarters

55 nickels

Explanation:

Equation 1

q + n = 135

q = 135 - n

Also we know the dollar values: 0.25q + 0.05n = 22.75, call this equation 2

Substituting in equation 2, we get

0.25 (135-n) + 0.05n = 22.75

33.75 - 0.25n + 0 05n = 22.75

-0.25n + 0.05n = 22.75 - 33.75

-0.20n = - 11

n = 11/0.20 = 55 = nickels

If q + n = 135

q = 135 - 55 = 80 = quarters