Kwik taxi service uses the units-of-activity method in computing depreciation on its taxicabs. Each cab is expected to be driven 140,000 miles. Taxi 10 cost $24,300 and is expected to have a salvage value of $700. Taxi 10 was driven 28,000 miles in 2016 and 33,000 miles in 2017. a) determine the depreciation cost. b) compute the depreciation expense for each year.