An entrepreneur plans to convert a building she owns into a video-game arcade.  Her main decision is how many games to purchase for the arcade.  From survey information, she projects total revenue per year as R = 10,000Q = 200Q2, where Q is the number of games.  The cost for each game (leasing, electricity, maintenance, and so on) is $4,000 per year.  The entrepreneur will run the arcade, but instead of paying herself a salary, she will collect profits.  She has received offers of $100,000 to sell her building and a $20,000 offer to manage a rival's arcade.  She recognizes that a normal return on a risky investment such as the arcade is 20%.
As a profit maximizer, how many games should she order?