The beginning inventory was 900 units at a cost of $10 per unit. Goods available for sale during the year were 3,900 units at a total cost of $43,200. in May 1,800 units were purchased at a total cost of $19,800. The only other purchase transaction occurred during October. The ending inventory was 1,650units. A. Calculate the number of units purchased in October and the cost per unit purchased in October. B. Calculate the cost of goods sold and the ending inventory under the following cost flow assumptions (using a periodic inventory system.)1. FIFO 2. LIFO