Answer:
There are 13 quarters, 67 nickels, and 22 dimes.
Step-by-step explanation:
The value of a quarter is $0.25, the value of dime is $0.10, and the value of a nickel is $0.05. Let there be q quarters, n nickels, and d dimes.
Let's write equations from the statements given:
"Ginny's piggybank contained $8.80 in quarters, dimes, and nickels.":
[tex]0.25q+0.1d+0.05n=8.80[/tex]
"there were two more than five times as many nickels as quarters":
[tex]5q+2=n[/tex]
"4 less than twice as many dimes as quarters":
[tex]2q-4=d[/tex]
Plugging in equation 2 and 3 into equation 1, we can solve for q:
[tex]0.25q+0.1(2q-4)+0.05(5q+2)=8.80\\0.25q+0.2q-0.4+0.25q+0.1=8.80\\0.7q=8.80+0.4-0.1\\0.7q=9.1\\q=\frac{9.1}{0.7}=13[/tex]
Substituting q = 13 into equation 2 will give us nickels:
[tex]n=5q+2\\n=5(13)+2\\n=67[/tex]
Substituting q = 13 into equation 3 will give us dimes:
[tex]d=2q-4\\d=2(13)-4\\d=22[/tex]
There are 13 quarters, 67 nickels, and 22 dimes.