Bob Company purchased a new machine on January 1, 2020, at a cost of $120,000. The company estimated that the machine has a salvage value of $10,000. The machine is expected to be used for 100,000 working hours during its 10-year life. Compute depreciation expense using the following methods in the year indicated. (a) Double declining-balance for 2020. (b) Units-of-production for 2020, assuming machine usage for 2020 was 12,000 hours. (Round depreciation per unit to the nearest cent.)