please read the instructions! tou can use excel

Question 6 (21 pts). A research lab purchased some equipments used in research and experimentation costing $300,000. The interest rate is 7%, salvage value is $30,000, and expected life is 5 years. Compute the PW of the depreciation deductions assuming: (a) Straight-line depreciation (b) Double declining balance depreciation (c) MACRS depreciation (5-year class) (d) Which method is preferred for determining the firm's taxes? (e) Which method is preferred for determining the firm's value? (f) Is using two accounting methods ethical