How would you calculate cost of goods sold? Whatitems make up cost of goods sold

How would you calculate cost of goods sold? Whatitems make up cost of goods sold? How does beginning and endinginventory affect cost of goods sold? What are the journal entries amerchandising organization would use to record the purchase andsubsequent sale of merchandise? How would these transactions differwith a periodic versus a perpetual inventory system? Why areperpetual inventory systems so much more popular today than back inthe early 1960s and earlier? Why would a company employing aperpetual inventory system still take a physical inventoryperiodically?