The question is incomplete:
The cost of a parking permit consists of a one-time administration fee plus a monthly fee. A permit purchased for 12 months costs $660. A permit purchased for 15 months costs $810.
What is the administration fee?
Answer:
$60
Explanation:
To calculate the administration fee, first you have to calculate the difference between the two permits and divide that by the month difference that is: 15-12= 3 to know the cost of the monthly fee:
$810-$660= 150
$150/3= $50
Now, you can multiply the monthly fee for 12 to know the total cost of the monthly fee for 12 months and then, subtract this from the cost of a permit purchased for 12 months to find the cost of the one-time administration fee:
$50*12= $600
$660-$600= $60
According to this, the administration fee is $60.