The plant and machinery account (at cost) of a business for the year ended 31 December 20X5 was as follows:Plant and machinery cost20X5 $ 20X5 $1 Jan Balance b/f 240,000 31 Mar Transfer to disposal account 60,00030 Jun Cash purchase of plant 160,000 31 Dec Balance c/f 340,000 400,000 400,000 The companys policy is to charge depreciation at 20% per year on the straight line basis, with proportionatedepreciation in the years of purchase and disposal.