16. If the estimated rate of gross profit is 40%, what is the estimated cost of the inventory on September 30, based on the following data? Sep. 1 Inventory (at cost) $140,000 Sep. 1-30 Purchases, net (at cost) 300,000 Sep. 1-30 Sales 400,000 a. $240,000 b. $255,000 c. $ 105,000 d. $200,000