a large company is planning to purchase equipment costing $220,000 and will depreciate it fully using straight-line depreciation over 8 years. the company expects that the investment will have an annual benefit of $54,000. each use of the equipment will also provide a benefit of $25. in 5 years, there will be no salvage value for the equipment. the company's combined marginal tax rate is 24%. based on 12% after-tax marr, how many uses of the equipment must the company have each year in order to justify its investment?