Padang Besar Inc. uses a perpetual inventory system. The company's beginning inventory of a particular product and its purchases during the month of January were as follows: Beginning inventory (Jan. 1) Purchase (Jan. 10) Purchase (Jan. 22) Quantity 50 25 25 Unit Cost $6 $7 $8 On January 25, Padang Besar sold 55 units of this product at $10 each. a Calculate the cost of goods sold on 25 January using each of the flow assumptions of LIFO, FIFO and average cost. (3 marks) b Determine the cost of the inventory at January 31 using LIFO, FIFO and Average cost flow assumptions: (3 marks) c. Explain the effect of using the three methods of inventories valuation in times of rising prices on the cost of goods sold. (2 marks) d. If other operating expenses are $100 for January. Calculate the income before tax for January using each of the inventory valuation method. (3 marks) e. A physical inventory count was made on 31 January revealed that only 41 units were on hand, show the journal entry to record the inventory shortage if FIFO method is used. (2 marks)