Can someone explain why 700 is the right answer?

The company's net income during the period was $1,000. The only expenses it had were cost of goods sold of $3,680 and wage expense of $2,000. The company wants to know how much its net income would be if it changed to the FIFO periodic method. Use the table with the company's purchases below to help calculate: May 1st Beginning inventory of 20 units at $150 a unit May 3rd Sold 17 units May 8th Purchased 30 units at $140 a unit May 19th Purchased 5 units at $120 a unit May 28th Sold 10 units 3,980 2,700 o 700 O-300