I only need explanation with the last part (Net sales, Cost of goods sold and Gross Profit). Thanks.

Pharoah Wholesalers uses a perpetual inventory system. Mar. Stellar Stores purchases $9,300 of merchandise for resale from Pharoah Wholesalers, terms 2/10,n/30,FOB shipping 1 point. 2 The correct company pays $165 for the shipping charges. 3 Stellar returns $1,200 of the merchandise purchased on March 1 because it was the wrong colour. Pharoah gives Stellar a $1,200 credit on its account. 21 Stellar Stores purchases an additional $14,000 of merchandise for resale from Pharoah Wholesalers, terms 2/10,n/30, FOB destination. 22 The correct company pays $185 for freight charges. 23 Stellar returns $300 of the merchandise purchased on March 21 because it was damaged. Pharoah gives Stellar a $300 credit on its account. 30 Stellar paid Pharoah the amount owing for the merchandise purchased on March 1. 31 Stellar paid Pharoah the amount owing for the merchandise purchased on March 21. Additional information: 3. Pharoah's cost of the merchandise returned by Stellar was $529. As the merchandise was not damaged, it was returned to Pharoah's inventory. 21 Pharoah's cost of the additional merchandise sold to Stellar Stores was $6,172. 23. Pharoah's cost of the merchandise returned by Stellar was $132. As the merchandise was damaged, it was put in the recycling bin. Prepare Pharoah Wholesalers' journal entries to record the sales transactions with Stellar. Remember to record the freight and cash receipt transactions as appropriate. (Credit account titles are automatically indented when the amount is entered. Do not indent manually. If no entry is required, select "No Entry" for the account titles and enter O for the amounts. Record joumal entries in the order precentart in the nmhlom I iet all dehit entrioe hefore rrarlit antriee I Calculate Pharoah's net sales, cost of goods sold, and gross profit for these sales. Net sales $ Cost of goods sold $ Gross profit $