Kavanaugh Limited purchased a delivery truck on January 2, 2017 for a total cost of $33,600. The delivery truck was expected to have a useful life of five years at which time it will have a residual value of $1,600. Kavanaugh estimated that the truck would be driven a total of 200,000 kilometers over the five years. Actual usage was as follows: 2017 38,000kms, 2018, 41,000kms, 2019, 44,000kms, 2020, 42,000kms and 2021, 37,000kms. Required: Calculate depreciation expense for each year using the following methods: a) Straight line b) Units of output c) Double diminishing balance