The Little Shell Co. purchased a drilling machine on 1 January 2019 for 174,000. The useful life of the machine is estimated at three years with a residual value at the end of this period of 24,000.

The total units expected to be produced over three years are 24,000:

Year 2019: 11,000 units

Year 2020: 7,000 units

Year 2021: 6,000 units

Using the most appropriate depreciation method, the depreciation expense for 2021 would be:

37,500

50,000

29,000

43,500