Illustration :

Jan 1 Beginning inventory 200 units @ $10 per unit

Jan 5 Purchased 300 units at $12 per unit

Jan 10 Sold 150 units at $40 per unit

Jan 15 Purchased 90 units at $15 per unit

Jan 20 Sold 300 units at $40 per unit

Required :

Perpetual Inventory System

Gross Profit Method for estimating inventory

Lower of Cost or Market Individual Item Based

Retail Average Cost