On 1 January 20X2, Carlton Ltd purchased an asset for $20,000. The asset is expected to have a residual value of $3,000 and a useful life of 10 years. The straight-line method is being used. On 1 January 20X5, Carlton changed the useful life of the asset. The remaining useful life of the asset is revised on 1 January 20X5 at 6 years and no residual value is expected anymore. Requirement: a) Explain how the transaction shall be treated under IAS 8 "Accounting policies, changes in accounting estimates and errors". b) Calculate the depreciation expense and the carrying amount of the asset on 31 December 20X5.