A car travels from point A to point B at a speed of 60 km/h, and immediately returns to point A at a speed of 40 km/h. What is the average speed of the car in km/h?
一辆汽车以60千米/时的速度从甲地到乙地，到达后立即以40千米/时的速度返回甲地．该车的平均速度是多少千米/时？
<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>