A car travels from A to B. It takes 5 hours to go and 4 hours to return. The speed when going is equal to the speed when returning.
一辆汽车从甲地到乙地，去时用了5小时，返回时用4小时，去时的速度是返回时速度的多少．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/5) / (1/4)</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>