Humboldt Sales had the following merchandise transactions during May. It uses a perpetual inventory system and FIFO inventory costing method. Beginning inventory was 10 units valued at $25 per unit (no journal entry required) May 5 Purchased 80 units of merchandise inventory on account for a total cost of $2,160, terms 1/15, FOB destination. May 10 Returned five units of defective merchandise purchased on May 5 and received full credit from the seller. May 11 Sold 30 units for $50 per unit on account, terms 3/10, n/30. May 15 Paid for the May 5th purchase. May 20 Received payment from the May 11th sale. Required: Prepare the journal entries to record these transactions on the books of Humboldt Sales. Leave a space between each journal entry. No explanations are needed. DATE ACCOUNTS DEBIT CREDIT May 5 May 10 May 11 May 15 May 20