please solve question 31-33 and explain how you get each answer

Use the following information to answer questions 31,32 and 33 . Lee Copporation had 400 units of inventory on hand at July 1, 2016, costing $20 each. Purchases and sales of goods during the month of July were as follows: Assuming Lec Corporation maintains the periodic inventory records. According to a physical count 400 units were on hand at July 31,2016 , 31. The cost of inventory at July 31,2016 , using the FIFO cost method, is a. \$11,000 b. $9.000 c. $8,000 d. 59,500 c. $11,200 32. The gross profit at Jaly 31, 2016, using the FIFO cost method is: a. 511,000 b. $8,000 c. $5,000 d. $9,000 33. The cost of inventory at July 31,2016 , using the weighted average cost method is: a. 511000 b. $9,000 c. $8,000 d. $9,500