What is the major difference between a periodic and a perpetual inventory system?

Powell company began the 2018 accounting period with $40,000 cash, $86,000 inventory, $60,000 common stock, and $66,000 retained earnings. during 2018, powell experienced the following events: sold merchandise costing $58,000 for $99,500 on account to prentise furniture store. delivered the goods to prentise under terms fob destination. freight costs were $900 cash. received returned goods from prentise. the goods cost powell $4,000 and were sold to prentise for $5,900. granted prentise a $3,000 allowance for damaged goods that prentise agreed to keep. collected partial payment of $81,000 cash from accounts receivable. required record the events in a statements model shown below. prepare an income statement, a balance sheet, and a statement of cash flows. why would prentise agree to keep the damaged goods?