Chemist Laboratories Ltd purchases from suppliers and sells to retailers a brand of cosmetic in the month of December 2017. All cosmetic items are identical. During the month of December 2017, the following inventory transactions took place in the Chemist Laboratories Ltd: Opening inventory recorded on 1 December 2017; 10 units @$22 Purchased on 1 December 2017; 20 units @$20 Sold 5 units on 10 December 2017 Sold 16 units on 12 December 2017 Purchased on 15 December 2017; 15 units @$18 Sold 12 units on 21 December 2017 Purchased on 25 December 2017; 10 units @$21 Chemist Laboratories Ltd purchased 45 units, sold 44 units and has 11 units on stock at the end of December. The company uses the perpetual inventory costs flow system to record the inventory. Required: Compute the costs of sales and ending inventory under the following cost flow methods: a) First in, First out (FIFO) method b) Weighted average cost method c) Last in, First out (LIFO) method