Supreme Auto Service opened a new service center three decades ago. At the time the center was preparing to open, new equipment was purchased totaling $366,000. Residual value of the equipment was estimated to be $46,000 after 20 years. The company accountant has been using straight-line depreciation on the equipment.

(a) How much was the annual depreciation for the original equipment (in $)? $ Correct: Your answer is correct.

(b) If the hydraulic lift had originally cost $14,640, what would its residual value (in $) be after 20 years? $ Incorrect: Your answer is incorrect.

(c) After six years of operation, the original hydraulic lift was replaced with a new model that cost $23,000. Book value was allowed for the old machine as a trade-in. What was the old hydraulic lift's book value when the replacement machine was bought (in $)? $ Incorrect: Your answer is incorrect.

(d) What was the book value of the equipment inventory at the six-year point, substituting the new hydraulic lift for the original after the new lift had joined the inventory (in $)? $