A car drives from place A to place B and then returns. The time ratio for the round trip is 5:4. How much is the speed increased when returning.
一辆汽车从甲地开往乙地后返回，往返所用时间比是5：4，返回时速度比去时提高了多少．
<gadget id="calculator">5 - 4</gadget>
<output>1</output>

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

<result>1/4 = around 0.25</result>