Inventory turnover ratio = 19.70 times. , has an inventory turnover of 15.9 times, a payables turnover of 9.7 times, and a receivables turnover of 8.2 times.There are 2 calculation formulas for days in AR: The simple method and the countback method. The ratio to determine number of days' sales in receivables is as follows. Days sales in receivables can be defined as the average number of days it takes to collect outstanding receiveable amounts from customers. In this exercise, we are asked to compute the number of days' sales in receivable ratio and how would it influence potential investors.