To build a road, the entire length (1/4) has been built, and the rest (1/5) has been repaired. At this time, there are still 6 kilometers away from the end point. What is the total length of this road in kilometers?
修一条公路，已经修完了全程的(1/4)，又修了剩余的(1/5)，这时距终点还有6千米，这条公路全长多少千米．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(3/4) * (1/5)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 - (1/4) - (3/20)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">6 / (3/5)</gadget>
<output>10</output>

<result>10</result>