I am having trouble with part A. I don't understand LIFO and even in class I had a hard time. I think I did FIFO correctly.. I'm pretty sure i can do part B.

Cost flow assumptions-FIFO, LIFO, and weighted average using a periodic system The following data are available for Sellco for the fiscal year ended on January 31, 2020: Required: a. Calculate cost of goods sold and ending inventory under the following cost flow assumptions (using a periodic inventory system): 1. FIFO. 2. LIFO. 3. Weighted average. Round the unit cost answer to two decimal places and ending inventory to the nearest $10. b. Assume that net income using the weighted-average cost flow assumption is $80,000. Calculate net income under FIFO and LIFO