conditioner costs

Culton Hair Salon sells an average of 20 bottles of hair conditioner weekly. There is a $2 5 cost to place an order with the distributor of the conditioner, and the conditioner costs the salon $2.50 per bottle. The annual holding cost rate is 18%, and the lead-time for delivery is one week. The salon desires a safety stock of five bottles and wishes to determine when an order should be placed and how many bottles it should order.