To build a 2-kilometer road, the full length (2/5) will be built on the first day, the full length (2/7) will be built on the second day, and the rest will be repaired on the third day. What fraction of the total length was repaired on the third day?
修一条2千米的公路，第一天修了全长的(2/5)，第二天修了全长的(2/7)，第三天要把剩下的全修完．第三天修了全长的几分之几？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (2/5) - (2/7)</gadget>
<output>11/35 = around 0.314286</output>

<result>11/35 = around 0.314286</result>