Answer is 6.66 but dont know how to get there

Mistook, Inc. began 2025 with inventory of $6,400 and by the end of the year, its inventory account had dropped to $5,800. During the year, Mistook purchased $40,000 of inventory. All of the inventory was purchased on account, and at the end of 2025 , Mistook still owed its suppliers $4,500. What was Mistook's inventory turnover ratio for 2025? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a 6.66 b 7.00 d 6.56