Suzie Sizewick works for a manufacturer of ballpoint pens, which come in packages of five pens each. Her job is to fill the packages with pens, and she is expected to process 100 packages an hour. The facility where Suzie works uses a kanban production system in which each container holds ten pen packages. It takes 15 minutes to receive the packages she needs from the previous workstation. The facility uses a safety stock of 12 percent. How many kanbans are needed for the filling process?