Build a 140-meter-long embankment and plan to complete it in 30 days. As a result, 35 meters were repaired in 5 days. According to this calculation, how many days can the task be completed in advance?
筑一条140米长的堤坝，计划30天完成．结果5天就修了35米．照这样计算，可以提前几天完成任务？
<gadget id="calculator">35 / 5</gadget>
<output>7</output>

<gadget id="calculator">140 / 7</gadget>
<output>20</output>

<gadget id="calculator">30 - 20</gadget>
<output>10</output>

<result>10</result>