A car goes back and forth between A and B with a speed of 40 km/h. If the average speed of the car is 48 km/h, what is the speed when it comes back?
汽车往返于A，B两地，去时速度为40千米/时，要想来回的平均速度为48千米/时，回来时的速度应为多少？
<gadget id="calculator">80 / 48</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">(5/3) - 1</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">40 / (2/3)</gadget>
<output>60</output>

<result>60</result>