A road repair team builds a road. It is planned to repair 35 meters per day, and it will be completed in 18 days. The actual repair is 42 meters per day, how many days can it be completed in advance?
一个修路队修一条路．计划每天修35米，18天修完．实际每天修42米，可以提前几天修完？
<gadget id="calculator">18 / 42</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">35 * (3/7)</gadget>
<output>15</output>

<gadget id="calculator">18 - 15</gadget>
<output>3</output>

<result>3</result>