please answer in proper order1 march purchase 100 units $50 each5 march purchase 400 units $55 each18 march purchase 120 units$60 each25 march purchase200 units $62 each9 march sales 420 unit $ 1(a). Compute the number of units available for sale in March. 1(b). Compute the number of units in ending inventory on March 31. 2 Compute the cost assigned to ending inventory using specific identif 1 answer