Jason uses his car for his job. He is allowed to depreciate the car 7% per year. IF the car was worth $23,000 new, in about how many years will the car be worth $3,000?

23000(.93)^n = 3000

.93^n = 3/23
log both sides

log (.39^n) = log (3/23)
n log .39 = log (3/23)
n = log (3/23) / log .93 = appr 28 years

Unrealistic question
1. Using a car for a job for 28 years
2. Such low level of depreciation.