Uncle Wang set off from the county seat to Wangzhuang Township to deliver fertilizers. It took 2 hours to go, the speed was 60 km/h, and the speed when returning was 40 km/h. How many hours did it take to return the same way?
王叔叔从县城出发去王庄乡送化肥．去的时候用了2小时，速度是60千米/时，返回时的速度是40千米/时．原路返回时用了多少小时？
<gadget id="calculator">2 / 40</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">60 * (1/20)</gadget>
<output>3</output>

<result>3</result>