Three different companies each purchased a machine on January 12008 for $42000. Each machine was expected to last five years or200000 hours. Salvage value was estimated to be $2000. All threemachines were operated for 50000 hours in 2008 55000 hours in2009 40000 hours in 2010 44000 hours in 2011 and 31000 hoursin 2012. Each of the three companies earned $30000 of cash revenueduring each of the five years. Company A uses straight-linedepreciation company B uses double-declining-balance depreciationand company C uses units-of-production depreciation.