A laptop computer is purchased for

Question

$5000
. Each year, its value is
70%
of its value the year before. After how many years will the laptop computer be worth
$300
or less

Answer 1

300 = 5000 (.7)^n

.06 = .7^n

log .06 = n log .7
so
n = log.06/log.7 = 7.89 years