ABC Corporation purchased a machine for $60,000 on January 1, 2022. The estimated useful life of the machine is 6 years, and it has no residual value. On December 31, 2022, the company changed the estimated useful life to 8 years. Calculate the following:
a) The depreciation expense for the year ended December 31, 2022, using the original estimated useful life of 6 years
b) The depreciation expense for the year ended December 31, 2022, using the revised estimated useful life of 8 years