Answer:
a. Using FIFO (First in, first out)
We have
Cost of goods sold = $1240 due to the fact that the first good bought cost $1240
Ending inventory = $1570
b. Using LIFO (last in, first out)
We have
Cost of goods sold = $1570 due to the fact that it was bought last
Ending inventory = $1240
c. Weighted average = (cost of good sold + ending inventory) ÷ 2
Thus
= (1240 + 1570) ÷ 2
= 2810 ÷ 2
= $1405