3. A truck driving over a flat interstate at a constant rate of 50 MPH gets 4 miles to the gallon. Fuel costs $.89 per gallon. For each mile per hour increase in speed, the truck loses a tenth of a mile per gallon in its mileage. Drivers get $27.50 per hour in wages, and fixed costs for running the truck amount to $11.33 per hour. What constant speed (between 50 MPH and the speed limit of 65 MPH) shoucl a dispatcher require on a straight run through 260 miles of Kansas interstate to minimize the total cost of operating the truck?
4. At Pizza Hut, they deliver for you, and in pizza boxes formed from 47 cm by 95 cm rectangluar pieces of cardboard by cutting out eight squares of equal size, four from each of the 95 cm edges: In the figure below, one square from the corner on the left, one from the middle of the edge, and two (side-by-side) from the corner on the right, to make a "lip" for the box. The result is then folded in the obvious fashion. (If it isn't obvious, order one with sausage and mushrooms to investigate.) How does one obtain the box of largest volume?
back to spreadsheet index page