6. Assume that at the beginning of 2019, West jet Airlines purchased a Airbus A380 aircraft at a cost of $25,000,000. West jet expects the plane to remain useful for five years (5,000,000 km) and to have a residual value of $5,000,000. West jet expects the plane to be flown 750,000 km the first year and 1,250,000 km each year during years 2 through 4, and 500,000 km the last year. Compute West jets first-year depreciation on the plane using the following methods: (20 marks) a) Straight-line b) Units-of-production c) Double-diminishing-balance