The distance between A and B is 240 meters. A car delivers goods from A to B, traveling at a speed of 40 kilometers per hour. On the way back, because it was empty, it was traveling at 60 kilometers per hour. What is the average speed of the car going back and forth in kilometers per hour?
甲乙两地相距240米，一辆汽车从甲地往乙地送货，去时以每小时40千米的速度行驶．返回时由于空载，以每小时60千米的速度行驶，这辆汽车往返的平均速度是每小时多少千米？
<gadget id="calculator">240 / 40</gadget>
<output>6</output>

<gadget id="calculator">240 / 60</gadget>
<output>4</output>

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

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">240 * (1/5)</gadget>
<output>48</output>

<result>48</result>