please help i don't understand how to use the FIFO and LIFO methods to find the cost of goods sold and cost of ending inventory

Tom Pryor is conducting an audit of the computerized inventory system used by Zix Corporation. Tom has inserted hypothetical data into the computer program that tracks inventory on a perpetual basis. Below are the hypotheical data inserted by Tom: Transaction Beginning inventory Purchase, day 1 Sale, day 2 Purchase, day 3 Sale, day 4 Units 10 5 6 8 9 Cost per unit $10 $11 $12 Compute the cost of Goods Sold and Cost of Ending Inventory using the following inventory costing methods: FIFO LIFO FIFO perpetual: Date Day 0 Day 1 Purchases Cost of Goods Sold Balance 10 X $10 = $100 Cost of Goods Sold Balance 10 X $10 = $100 5 X $11 = $55 Day 2 Day 3 8 X $12 = $96 Day 4 Ending LIFO perpetual: Date Day 0 Day 1 Purchases 5 X $11 = $55 Day 2 Day 3 8 X $12 = $96 Day 4 Ending