could you help solve this, how do I take up sales

The following information has been extracted from the records of Steven's Stationery about one of its popular products. Steven's Stationery uses the perpetual inventory system. It's annual reporting date is 3/ December. lenore GST No. of units Unit cost 2015 Jan Beginning balance 900 ST.DO 6 Purchases 400 Feb. THIS Sales @1 8 12.00 per wait 1000 7.05 March17 Purchases 1 100 17 35 April 24 Purchases returns 80 May Sales @ $12 10 per unit 700 June 26 Purchases 8 400 7.50 Aug 17 sales @ $15.15 per unit 1 500 Aug. 19 Sales returns @ Sis 25 per unit 20 Sept. IT Sales @ $13.50 per unit 3 500 Oct 6 Purchases 500 $.00 Dec. 11 "Sales (ol S1 5:00 pen wall 3190