On January 1, 2020, Rasmus Mining Ltd. purchased new mining equipment costing $386,000, which will be depreciated on the assumption that the equipment will be useful for four years and have a residual value of $28,000 when the company is finished using it. The estimated output from this equipment, in tonnes, is as follows: 2020—102,400; 2021—32,200; 2022—97,300; 2023—54,500. The company is now considering possible methods of depreciation for this asset.

Required

a. Calculate what the depreciation expense would be for each year of the asset’s life, if the company chooses:

i. The straight-line method 

ii. The units-of-production method 

iii. The double-diminishing balance method

b. Briefly discuss the criteria that a company should consider when selecting a depreciation method.