Question

On federal income tax returns, self-employed people can depreciate the value of business equipment. Suppose a computer valued at $2765 depreciates at a rate of 30% per year. Estimate the number of years it will take for the computer's value to be less than $350.

5.8 yr
10.3 yr
2.5 yr
7.2 yr

Answer 1

If it depreciates 30% each year it must retain 70% of its value each year.

Equation:
A(t) = A(0)*0.70^t
Your Problem:
2765(0.70)^t < 350
0.70^t < 0.1265823...
Taket the log of both sides to get:
t*log(0.70) < log(0.1265823..)
Solve for "t":
t > -0.897627.. / -0.1549020
t > 5.7948 years

Answer 2

5.8 yr ........................