During her first year of subscribing to a newspaper, christie paid $48. during each subsequent year, the annual cost was 1.5 times the price paid the previous year. which of the following equations may be used to calculate the total cost, c, of subscribing to the newspaper after n years?

Assuming that n = 0 when we focus on the first year, C = $48*1.5^n would represent the cost for the 2nd, 3rd, 4th, , years.

Check:  $48(1.5)^0 = $48(1) = $48 (correct)
             $48(1.5)^1 = $48(1.5) = $72 (correct)
              $48(1.5)^2 = $48(2.25) = $108

These results are as expected.