A contractor has to choose one of the following alternatives in performing earthmoving contracts: A. Buy a truck for $35,000. Salvage value is expected to be $8,000 at the end of its 7-year depreciable life. Maintenance is $2,500 per year. Daily operating expenses are $200. B. Hire a similar unit for $550 per day Based on a 10% after tax-rate of return, how many days per year must the truck be used to justify the purchace? base calculations on straight line depreciation and a 40% income tax rate. Answer should be 30 days...