It is planned to build a road 30 meters a day, and it will be completed in 15 days. In fact, 75 meters were repaired in the first 3 days. According to this calculation, how many days will it take to complete the road? (Answer with proportional knowledge)
修一条路计划每天修30米，15天修完．实际前3天修了75米，照这样计算，修完这条路共需多少天？(用比例知识解答)
<gadget id="calculator">30 * 15</gadget>
<output>450</output>

<gadget id="calculator">75 / 3</gadget>
<output>25</output>

<gadget id="calculator">450 / 25</gadget>
<output>18</output>

<result>18</result>