Question

A new automobile is purchased for $20,000. If V = 20,000 (0.8)^x, gives the car's value after x years, approximately how long will it take for the care to be worth half of its purchase price?

a. 3 years
b. 4 years
c. 5 years
d. 6 years

Answer 1

That's not an answer though.

Answer 2

i no let me redo my work =(

Answer 3

ha ha. I had the right work i just punched wrong button in calculator.

V=20,000*(0.8)^x

10,000=20,000*(0.8)^x

log(10,000/20,000)=x*log(0.8)

x=[log(10,000/20,000)/log(0.8)]

x=3.10628 =)