A ship travels from A to B. It takes 5 hours to go and 8 hours to return. The return speed is equal to the speed
一艘轮船从甲地到乙地，去时用了5小时，返回时用了8小时，返回的速度相当于去时的多少
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

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

<gadget id="calculator">(1/8) / (1/5)</gadget>
<output>5/8 = around 0.625</output>

<result>5/8 = around 0.625</result>