The Rate of Inventory Turnover Is Eight Times When

The rate of inventory turnover is eight times when:

A) Net purchases are £120,000 and closing inventory is £15,000
B) Sales are £160,000 and average inventory at selling price is £20,000
C) Purchases are £320,000 and average inventory at cost is £40,000
D) Cost of goods sold is £240,000 and average inventory at cost is £30,000