Mo bought a new car from a showroom. The value, $P, of Mo's car is modelled by

P(t)= 20000(0.9)^(kt)+ 1000, where t is the

number of years since Mo bought the car.

a.) Find the price that Mo paid for the car

After three years, the car was valued at

$16 000.

b.) Find k.

Mo will sell his car when it is worth $5000.

c.) Determine the number of years, after

buying the car, that Mo sells it.