The transportation rate of JAC brand trucks is 2.5 times that of tractors, and the transportation rate of large container vehicles is 3 times that of JAC brand trucks. It takes 6 hours to transport a pile of goods with JAC brand vehicles. How many hours will it take to transport the other half in a large container truck?
JAC牌货车的运输率是拖拉机的2.5倍，大型集装车的运输率是JAC牌货车的3倍，现有一堆货物，用JAC牌车运，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">15 / 5</gadget>
<output>3</output>

<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">6 * (2/5)</gadget>
<output>12/5 = around 2.4</output>

<gadget id="calculator">(12/5) / 2</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">9 + (6/5)</gadget>
<output>51/5 = around 10.2</output>

<result>51/5 = around 10.2</result>