Need help. Not sure how to work this problem.

Open Space Furniture began June with merchandise inventory of 45 sofas that cost a total of $31,500. During the month, Open Space purchased and sold merchandise on account as follows:

June 7 Purchases 25 sofas @ $ 750 each

14th sale 30 sofas @ $1150 each

18th purchases 50 sofas @ $775 each

27th sale 35 sofas @ $1200 each

a perpetual inventory record, using the LIFO inventory costing method, and determine the company's cost of goods sold, ending merchandise inventory, and gross profit.