mn = 63 , n=6 , n=3

Q1.|| [5 points) A company purchases a piece of equipment for $15,000. After nine years, the salvage value is $900. The annual insurance cost is (5+0.1xn)% of the purchase price, the electricity cost is $600/yr, and the maintenance and replacement parts cost is $120/yr. The annual interest rate is 8%. Neglecting taxes, what is most nearly the present worth of the equipment if it is expected to save the company $4500 per year