To build a road, the full length (1/6) was built on the first day, and the full length (1/4) was built on the second day. At this time, there is still 20 meters away from the midpoint. How many meters is the total length of this road?
修一条路，第一天修了全长的(1/6)，第二天修了全长的(1/4)，这时离中点还有20米，这条路全长多少米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

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

<gadget id="calculator">(1/2) - (1/6) - (1/4)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">20 / (1/12)</gadget>
<output>240</output>

<result>240</result>