Question

From 1982 to 1992, the cost of manufacturing a PC has decreased by about the same percentage each year. The cost, C (in dollars), in year t can be modeled by C=3000(5/6) where t= 0 corresponds to 1982. Find the ratio of the cost in 1990 to the cost in 1985.

Answer 1

you have to do c + t times 5/6
then you have to do
$1982 - 1992 = 10 years$