On January 1, 2020 Milky Factory purchased new equipment for $600. The equipment is expected to be used for 500 hours over 4 years. Residual value is expected to be $100. During 2020 the equipment was used for 120 hours. Required: Compute the following $ Depreciable cost Depreciation expense for 2020 using straight-line depreciation Depreciation expense for 2020 using units of activity depreciation $