OliverCompany purchased tool sharpening equipment on October 1 for $138,000. The equipment was expected to have a useful life of three years or 13,000 operating hours, and a residual value of $7,700. The equipment wasused for 1,650 hours during Year 1, 4,700 hours in Year 2, 3,850 hours in Year 3, and 2,800 hours in Year 4.
Determine the amount of depreciation expense for the years ended December 31, Year 1, Year 2, Year 3, and Year 4, by
a.the straight-line method
b.the units-of-activity method
c.the double-declining-balance method.