You have a truck and 300 gallons of gas. You have to transport the gas, using the truck, to sell at the market 100 miles away. Your truck can carry at most 100 gallons of gas at any time, and it consumes 1 gallon of gas for every mile it travels. What's the maximum amount of gas you can get to the market? You have spare containers so you can leave gas along the way and come back and pick it up if you like. For example, you could load up your truck with 100 gallons of gas and drive to the market. But then when you got to the market, you'd have no gas to sell, and worse, you would be stranded and could not get back to the rest of your gas.