To build a road, the road was repaired in 5 days (20/21), how much was the road repaired in 3 days.
修一条公路，5天修了公路的(20/21)，3天修公路的多少．
<gadget id="calculator">20 / 21</gadget>
<output>20/21 = around 0.952381</output>

<gadget id="calculator">(20/21) / 5</gadget>
<output>4/21 = around 0.190476</output>

<gadget id="calculator">(4/21) * 3</gadget>
<output>4/7 = around 0.571429</output>

<result>4/7 = around 0.571429</result>