Li Village plans to build a cement road, and 40% of it was completed in the first 3 days. According to this calculation, how many days will it take to build this road?
李村计划修一条水泥路，前3天完成了40%，照这样计算，修这条路一共要用多少天？
<gadget id="calculator">2 / 15</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">1 / (2/15)</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>