The data for inventory for an item are: 

September 1st- Beginning inventory   40 units at $40

September 4th-sold                            30 units 

September 10th- purchased                30 units at $42

September 17th- Sold                           20 units

September 30th- purchased                20 unites at $44 

1) Using the perpetual inventory system, costing by the LIFO method, what is the cost of the inventory of 40 units on September 30th?

2) Using the perpetual inventory system, costing by the FIFO method, what is the cost of the inventory of 40 units on September 30? 

3) Using the periodic inventory system, costing by the average cost method, what is the cost of the merchandise inventory of 40 units on September 30?