10. Zaynab Company uses a periodic inventory system. Its records show the following for the month of May, in which 60 units were sold. Units Unit Cost Total Cost May 1 Inventory 30 OMR 9 OMR 270 15 Purchase 22 11 242 24 Purchase 38 12 456 Totals 90 OMR968 Instructions: Compute the ending inventory at May 31 and cost of goods sold using the FIFO, LIFO and Average-cost methods