PERIODIC INVENTORY SYSTEM. THe portion in red ONLY.

PERIODIC INVENTORY SYSTEM.  I only need assistance with the PERIODIC INVENTORY SYSTEM portion of this assignment.  THe portion in red ONLY.  Please explain the attached problem.  I am having a hard time getting this one and I really need assistance.QS 5-1:Prepare journal entries to record each of the following purchases transactions of a merchandising company.  Show supporting calculations and assume a perpetual inventory system.  Mar. 5    Purchased 600 units of product with a list price of $10 per unit.  The purchase is               granted a trade discount of 20%; term of the sale are 2/10, n/60; invoice is dated               March 5.Mar. 7    Returned 25 defective units from the March 5 purchase and received full credit.Mar. 15  Paid the amount due from the March 5 purchase, less the return on March 7.  QS 5-9A: Refer to QS 5-1 and prepare journal entries to record each of the merchandising transactions assuming that the periodic inventory system is used.  QS 5-2:Prepare journal entries to record each of the following sales transactions of a merchandising company.  Show supporting calculations and assume a perpetual inventory system.Apr.  1    Sold merchandise for $3,000, granting the customer terms of  2/10, EOM;                invoice dated April 1.  The cost of the merchandise is $1,800.Apr.   4   The customer in the April 1 sale returned merchandise and received credit $600.                  The merchandise, which had cost $360, is returned to inventory.Apr. 11    Received payment for the amount due from the April 1 sale less the return on                 April 4.        QS 5-10A:  Refer to QS 5-2 and prepare journal entries to record each of the merchandising transactions assuming that the periodic inventory system is used.QS 5-1:Prepare journal entries to record each of the following purchasestransactions of a merchandising company. Show supporting calculationsand assume a perpetual inventory system.Purchased 600 units of product with a list price of $10 perunit. The purchase isgranted a trade discount of 20%; term of the sale are2/10, n/60; invoice is datedMarch 5.Returned 25 defective units from the March 5 purchase andreceived full credit.Mar. 15 Paid the amount due from the March 5 purchase, less the returnon March 7.QS 5-9A:Refer to QS 5-1 and prepare journal entries to record each of themerchandising transactions assuming that the periodic inventory systemis used.QS 5-2:Prepare journal entries to record each of the following salestransactions of a merchandising company. Show supporting calculationsand assume a perpetual inventory system.Sold merchandise for $3,000, granting the customer terms of2/10, EOM;invoice dated April 1. The cost of the merchandise is$1,800.The customer in the April 1 sale returned merchandise andreceived credit $600.The merchandise, which had cost $360, is returned toinventory.Received payment for the amount due from the April 1 saleless the return onApril 4.QS 5-10A:Refer to QS 5-2 and prepare journal entries to record each of themerchandising transactions assuming that the periodic inventory systemis used.