Answer: $530
Explanation:
In the FIFO inventory method, the first purchased inventory is the first to be sold.
A total of 55 inventory was purchased and a total of 30 was sold off. The 30 inventories sold would be taken from the first purchased inventories which are the 20 and 30 purchased on the 1st and 10th of November respectively. The cost of the 25 inventories would be the cost of purchasing the inventory bought on the 10th and 30th of November.
The cost of the 25 inventories :
20 × $21 = $420
5 × $22 = $110
= $530