The following transactions all relate to Sharper Inc.'s purchase of merchandise inventory on December 10. 1. Purchased inventory on December 10 with a list price of $3,750, a trade discount of 20%, and with terms 2/10,n/30. 2. Returned $500 of inventory to the supplier on December 15 . 3. Paid $2,000 cash on December 19 to the supplier. 4. Paid the remaining balance to the supplier on January 5 of the following year. Required a. Prepare journal entries for the transactions 1 through 4 , assuming that the company uses the perpetual inventory system and the net method. Include any adjusting entry required on December 31. b. Prepare journal entries for the transactions 1 through 4 , assuming that the company uses the periodic inventory system and the net method. Include any adjusting entry required on December 31