Beginning inventory, purchases, and sales data for Commodity Y for June are presented below: Inventory, June 1 15 units at R40 each Sales, June 9 8 units 17 6 units 28 Purchases, June 59 19 6 units 10 units at R42 each 10 units at R43 each REQUIRED: (a) (b) (c) Assuming that the perpetual inventory system is used, costing by the moving average method, determine the cost of the inventory balance at 30 June. Show clear workings. Work to the nearest cent. Assuming that the periodic inventory system is used, costing by the weighted average method, determine the cost of the 15 units in the physical inventory at 30 June. Work to the nearest cent. Determine the amount of the difference between the inventory cost in (a) and (b), and explain the reason for the difference.