The road repair team builds a road. After repairing the full length (2/5), there is still 10 kilometers away from the midpoint of the road. How long is the road in kilometers?
修路队修一条公路，修了全长的(2/5)后，距离这条公路的中点还有10千米，这条公路长多少千米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/2) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">10 / (1/10)</gadget>
<output>100</output>

<result>100</result>