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.

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

Step-by-step 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.