Can someone explain step-by-step FIFO and LIFO to me? I don't understand!

1. Calculate ending inventory using FIFO and LIFO: Beginning inventory has $5,000 units with a value of $25,000. Early in the year you bought 10,000 units at $10 each. Ending inventory consists of 3,000 units. What is the ending inventory value under FIFO and LIFO?

2. Calculate the total amount to be assigned to cost of goods sold for the fiscal year ended September 30, and ending inventory on September 40 under FIFO and LIFO. (sorry the picture is kinda dark)

Thank you so much