Answer: 22 quarters
Step-by-step explanation:
Let N be the number of nickels.
Then the number of quarters is (55-N)
The nickels contribute 5N cents to the total.
The quarters contribute 25*(55-N) cents to the total.
5N + 25*(55-N) = 715
5N + 1375 - 25N = 715
-20N = 715 - 1375 = -660
[tex]N=\frac{-660}{-20}[/tex]
[tex]=33[/tex]
[tex]55-33=22[/tex]
So there is 22 quarters inside the jar.
Check to see if my answer is correct-
33*5 + 22*25 = 715 cents
