Aristotle Ltd holds a particular type of tyre for which annual sales are $468,000. Each tyre is sold forcostplus 50%. The tyre supplier takes six weeks to supply the tyre from the date that an order is raised by Aristotle Ltd. Each tyrecosts $40. The business holds 600 units of the tyre as a safety buffer and wishes to retain this buffer at all times. At what level of inventory should the business reorder this tyre?