A production cell at Canderberry Candle facility operates 5 hours per day and uses a pull method to supply wicks to the assembly line. The wicks are used at a rate of 300 per day. Each container holds 20 wicks and usually waits 20 minutes in the production cell. Management wants a safety stock of 10 percent. How many containers should be used at the Canderberry Candle facility for purposes of pull production?