On January 1, 2021, Canseco Plumbing Fixtures purchased equipment for $40,000. Residual value at the end of an estimated 7 year service life is expected to be $12,000. The company expects the equipment to operate for 12,500 hours. Required: a. Calculate depreciation expense for 2021 and 2022 using sum-of-the-years’-digits assuming the equipment was purchased on January 1, 2021. b. Calculate depreciation expense for 2021 and 2022 using sum-of-the-years’-digits assuming the equipment was purchased on March 31, 2021.