An engineering team repaired 20% of the total length of a canal in the first 3 days. At this speed, it only takes a few more days to complete it?
某工程队修一条水渠，前3天修了全长的20%，照这样的速度，只要再修几天就能完成？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 / (1/5)</gadget>
<output>15</output>

<gadget id="calculator">15 - 3</gadget>
<output>12</output>

<result>12</result>