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? $50 $54 $55 $60

Find out the what is the administration fee .

To prove

Let us assume that the one-time administration fee be x.

Let us assume that the monthly fee be y.

As given

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.

Than the equation becomes

x + 12y = 660

A permit purchased for 15 months costs $810.

x + 15y = 810

Than subtracted x + 12y = 660 from x + 15y = 810 .

x - x + 15y - 12y = 810 - 660

3y = 150

y = 50

Put value of y in the equation x + 12y = 660 .

x + 12 × 50  = 660

x = 660 - 600

x = $60

Therefore the administration fee be $60 .