An express train and a slow train are traveling towards each other. The length of the express train is 270 meters, and the length of the slow train is 360 meters. It takes 12 seconds for the person in the fast car to see the slow car passing by, so how many seconds does it take for the person in the slow car to see the fast car pass by?
一列快车和一列慢车相向而行，快车的车长是270米，慢车的车长是360米．坐在快车上的人看见慢车驶过的时间是12秒，那么慢车的人看见快车驶过的时间是多少秒？
<gadget id="calculator">360 / 12</gadget>
<output>30</output>

<gadget id="calculator">270 / 30</gadget>
<output>9</output>

<result>9</result>