The following table lists the sale and purchase records of an inventory item, i.e. souvenir packs, which were made by the souvenir shop of the Sky Travel Ltd. in the month of March 2020. Assume the beginning inventory on the first day of March consisted of 6 units, which were purchased at a unit cost of $100 each, and that the periodic inventory system is in use. Transaction date Units Unit Total Units 2020 purchased cost cost sold Mar 8 8 $108 $864 Mar 15 7 Mar 23 10 $120 $1,200 Mar 30 9 (Show all your workings clearly in appropriate tabular formats) (a) Calculate the cost of sales by using the first-in-first-out (FIFO) method. (5 marks) (b) Calculate the cost of sales by using the last-in-first-out (LIFO) method. (4 marks) (c) Calculate the cost of sales by using the weighted average cost method. (4 marks) (d) Distinguish between the periodic inventory system and the perpetual inventory system. Give an example to illustrate. (7 marks) Total 20 marks)