Old Japan Pottery Co. produces glazed bowls and jugs using two furnaces, one to fire the clay and another to set the glaze. A bowl takes 2 hours to fire in the first furnace, and 1.5 hours for the glaze to set in the second furnace. A jug takes 3 hours to fire in the first furnace, and does not need to glaze in the second furnace. The first furnace has 42 hours of available time, while the second furnace has 22.5 hours of available time. A bowl sells for $30 and a jug sells for $42. How many bowls and jugs should they create to maximize their gross profit? Formulate a linear programming model to solve this problem. List the extreme points and determine the solution graphically. You do not need to submit your graph.