19. Equipment with a cost of $160,000, an estimated residual value of $10,000, and an estimated life of 4 years, was purchased on April 1, 2015. If the straight-line method is used, the depreciation expense for calendar 2015 is (a) $40,000. (b) $37,500. (c) $30,000. (d) $28,125. (e) None of the above. 20. A truck was purchased for $40,000 and it was estimated to have a $4,000 residual value. Using the straight-line method, monthly depreciation expense of $600 was recorded. Therefore the annual depreciation rate expressed as a percentage is (a) 2%. (b) 17%. (c) 18%. (d) 20%. (e) None of the above