To build a 450-meter-long road, 75 meters were built in 3 days. According to this calculation, how many days will it take to finish the rest?
修一条长450米的公路，3天修了75米，照这样计算，余下的要几天才能修完？
<gadget id="calculator">75 / 3</gadget>
<output>25</output>

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

<result>18</result>