To build a section of road, the full length (1/5) was repaired on the first day, 500 meters was repaired on the second day, and exactly 40% of the total length was repaired in two days. How long is this road in kilometers?
修一段路，第一天修了全长的(1/5)，第二天修了500米，两天正好修了全长的40%．这条路全长多少千米？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">(2/5) - (1/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">500 / (1/5)</gadget>
<output>2_500</output>

<result>2_500</result>