The engineering team repairs a canal and sends 25 people to do it, which can be completed in 120 days. If the work efficiency remains the same, how many days will it take to send 30 people to do it? (Answer with proportional knowledge)
工程队修一条水渠，派25人去做，120天可以完成．如果工作效率不变，派30人去做，多少天可以完成？(用比例知识解答)
<gadget id="calculator">120 / 30</gadget>
<output>4</output>

<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<result>100</result>