The transportation rate of Jiefang vehicles is 2.5 times that of tractors, and the transportation rate of large container vehicles is 3 times that of Jiefang vehicles. It takes 6 hours to transport a pile of goods with Jiefang vehicles. How many hours will it take to transport the other half in a large container?
解放牌汽车的运输率是拖拉机的2.5倍，大型集装车的运输率是解放牌汽车的3倍，现有一堆货物，用解放车运，要6小时，如果改用拖拉机运一半，再用大型集装车运另一半，一共要用多少小时？
<gadget id="calculator">7.5 + 1</gadget>
<output>8.5</output>

<result>8.5</result>