A town post office has \(\$ 800,000\) available for the purchase of delivery vehicles. There are two models, a Jeep style and a van style, under consideration. Each Jeep costs \(\$ 8000\) and each van costs \(\$ 10,000\). Estimated annual maintenance costs per vehicle are \(\$ 800\) and \(\$ 600\), respectively, for jeeps and vans. The town will allocate \(\$ 80,000\) annually for maintenance. If the jeep achieves 25 miles per gallon of gasoline and the van achieves 20 miles per gallon, how many of each type of vehicle should the town buy in order to maximize the total among all vehicles of miles per gallon of gasoline? Can the problem of maximizing average gas mileage per vehicle be treated by the methods of this chapter?