what would be the cost of goods sold, assuming the FIFO method is used in periodic inventory system? show work please

The following information was taken from the inventory records of Helena Ltd. Dates Inventory - Feb 1 Purchases - April 1 Purchases Units available for sale - Inventory units 100 units at $3.00 300 units at $3.10 200 units at $3.20 600 units July 15 Sales Sales May 10 November 15 200 units at $6.00 100 units at $6.10 ARAWAN