A car goes back and forth between A and B. It takes 5 hours to go there, but the speed when it comes back increases by 1/8, which is how many hours less than when it went there.
一辆汽车往返甲乙两地，去时用了5小时，回来时的速度提高了8分之1，比去时少用了多少小时．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 + (1/8)</gadget>
<output>9/8 = around 1.125</output>

<gadget id="calculator">(1/5) * (9/8)</gadget>
<output>9/40 = around 0.225</output>

<gadget id="calculator">1 / (9/40)</gadget>
<output>40/9 = around 4.444444</output>

<gadget id="calculator">5 - (40/9)</gadget>
<output>5/9 = around 0.555556</output>

<result>5/9 = around 0.555556</result>