It takes 3 hours for a car to go from Wuping to Longyan, and 2 hours to return. What is the average round-trip speed?
汽车从武平到龙岩，去时用了3小时，返回用了2小时，往返平均速度是多少．
<gadget id="calculator">1 * 2</gadget>
<output>2</output>

<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>