Bart Wurst runs the only hot-dog stand in a large park in a large boring town. On Sundays people in this town all sit in the park and sunbathe. For any t between 0 and 30, the number of people who are sitting within t minutes of Bart's stand is 10t2. People in Bart's town are lazy and hate to walk. They think that every minute of walking they do is as bad as spending $.10. Everybody in the park has a reservation price of $1 for a hot dog, where the cost of a hot dog includes the subjective cost of walking as well as the money price they have to pay when they get there. (Nobody has ever thought of fetching a hot dog for someone else.) Find a formula for the demand curve for Bart's hot dogs. Explain how you got it.