The distance between A and B is 240 kilometers. It takes a car 6 hours to drive from A to B, and 4 hours to return. What is the average speed of this car round trip in km/h.
甲、乙两地相距240公里，一辆汽车从甲地开往乙地用了6小时，返回时用了4小时．这辆汽车往返的平均速度多少公里/小时．
<gadget id="calculator">240 * 2</gadget>
<output>480</output>

<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">480 / 10</gadget>
<output>48</output>

<result>48</result>