Sam Lawn Maintenance uses a perpetual inventory system. At December 31, the perpetual inventory records indicate the following quantities of a particular mower. Purchases: March 1 80 units @ $100 8,000 March 10 March 100 units @ $110 11,000 20 20 units @ $120 2,400 A year end physical inventory, however shows only 199 of these lawn mowers on hand. Determine the cost of inventory on hand at March 31 and the cost of goods sold for March under: Instructions A. LIFO and B. Average-cost