Answer:
D.) $60
Explanation:
First, use the given information to calculate the monthly charge:
15 months-12 months = 3 months
$810-$660=$150
So, 3 months of parking costs $150 which translates to $50 a month. Using this information and the original given information, the administration fee can be calculated:
12($50)+x=$660
$600+x=$660
$600+x-$600=$660-$600
x=$60
and
15($50)+x=$810
$750+x=$810
$750+x-$750=$810-$750
x=$60
The administration fee is $60