A road construction team plans to build 720 meters of road in one month (30 days), but actually built 180 meters in the first 5 days. According to this calculation, how many days can the road construction task be completed in advance.
一个筑路队计划一个月(30天)修路720米，实际前5天就修了180米，照这样计算，完成修路任务可以提前多少天．
<gadget id="calculator">180 / 5</gadget>
<output>36</output>

<gadget id="calculator">720 / 36</gadget>
<output>20</output>

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

<result>10</result>