A person drives to and from A and B at speeds of 60 kilometers per hour and 40 kilometers per hour respectively. What is the average speed of coming and going in kilometers per hour?
某人开车往返于A，B两地，来去的速度分别为每小时60千米和每小时40千米．则来去的平均速度为每小时多少千米．
<gadget id="calculator">1 * 2</gadget>
<output>2</output>

<gadget id="calculator">1 / 60</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">1 / 40</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">(1/60) + (1/40)</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">2 / (1/24)</gadget>
<output>48</output>

<result>48</result>