A car travels the whole journey in 3 hours (2/5), how many hours does it take for the car to travel the whole journey.
一辆汽车3小时行全程的(2/5)，这辆汽车行完全程用多少小时．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) / 3</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">1 / (2/15)</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>