Sarah's Organic Soap Company makes four kinds of organic liquid soap - "regular,", "lavendar", "citrus", and "tea tree". Demand for the four scents are 200, 100, 100, and 50 kg per hour respectively. Sarah's production process can produce any soap at the rate of 475 kgs per hour, but 1.5 hours are needed to switch between scents. During those switchover times the process doesn't produce any soap. Sarah wants to choose a production schedule that (1) cycles repeatedly through the four scents, (2) meets the required demand and (3) minimizes the amount of inventory held.
How many kgs of "regular" should Sarah produce before switching over to another scent? ______kgs