Syarikat Layang uses the LIFO (Last-in, First-out) costing method for its perpetual inventory system. It had inventory on 1st January 2021 consisting of 400 articles bought at RM4 each. The purchases during the month of January consisted of 800 at RM4.20 each purchased on 8 January, and 2,000 at RM3.80 each on 18 January. It sold 2,400 at RM5.00 each on 28 January. 40 of those sold were returned in perfect condition on 31 January. The returned goods were bought on 18 January. Required: a. i. Calculate, by means of an inventory account the number and cost of the articles held in inventory during January 2021. (11 mark) ii. The unit price and total cost of the inventory. (3 marks) b. Show the trading account for the month ended 31 January 2021. (6 marks)