Tickets for the new ice hockey game went on sale last Sunday morning at the Barclays Center box office. People arrived at the Barclays Center at a rate of 300 per hour starting at 5am until noon, and a queue formed in front of the box office. There was no balking or reneging. At 9am, the box office opened and began selling tickets through 8 ticket windows, each of which served customers at a steady rate of 60 per hour. The box office closed at midday, at which point all remaining people in line were turned away.
I) How many people did the box office serve on Sunday morning?
II) How many people were in line when the ticket office closed?
III) How many people were in line when the line was at its longest?
IV) What is the inventory build-up graph?