The distance between A and B is 720 kilometers. A car drives from A to B, and it travels 240 kilometers in the first 3 hours. At this speed, how many hours does it take for the car to drive from A to B?
甲乙两城相距720千米，一辆汽车从甲城开往乙城，前3小时行驶了240千米，照这样的速度，这辆汽车从甲城开到乙城需要几小时？
<gadget id="calculator">3 * 720</gadget>
<output>2_160</output>

<gadget id="calculator">2_160 / 240</gadget>
<output>9</output>

<result>9</result>