A train of passenger cars and a train of freight trains depart from two stations A and B at the same time. The speed ratio of the passenger cars and the freight trains is 3:2. The passenger train travels for 6 hours to arrive at Station B. How many hours does it take for the truck to arrive at Station A?
一列客车和一列货车同时从甲乙两站相向开出，客车与货车速度比是3：2，客车行驶6小时到达乙站，货车行驶多少小时到达甲站？
<gadget id="calculator">3 * 6</gadget>
<output>18</output>

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

<result>9</result>