The speed of the slow train is (5/9) that of the fast train. At the same time, the distance of the fast train is longer than that of the slow train ((())/(())).
慢车的速度是快车的(5/9)，在同一时间里，快车的路程比慢车多((())/(()))．
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">1 / (5/9)</gadget>
<output>9/5 = around 1.8</output>

<gadget id="calculator">(9/5) - 1</gadget>
<output>4/5 = around 0.8</output>

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