Can someone explain the fifo and lifo for this and how did the calculation haplen for total as well.

Trey Monson starts a merchandising business on December 1 and enters into the following three inventory purchases. Monson uses a perpetual inventory system. Also, on December 15, Monson sells 15 units for $27 each. PurchasesonDecember7PurchasesonDecember14PurchasesonDecenber2110unitse$13.00cost20unitse$19.00cost15units$21.00cost. QS 5-11 (Algo) Perpetual: Assigning costs with FIFO LO P1 Required: Determine the costs assigned to the December 31 ending inventory based on the FIFO method. Trey Monson starts a merchandising business on December 1 and enters into the following three inwentory purchases. Monson uses a perpetual inventory system. Also, on December 15, Monson sells 15 units for $27 each. PurchasesonDecember.7PurchasesonDecember14PurchasesonDecenber2110units$13.00cost20units$19.60cost15units$1.00cost QS 5-12 (Algo) Perpetual: Inventory costing with LIFO LO P1 Determine the costs assigned to ending inventory when costs are assigned based on the LIFO method