Team A and Team B jointly build a canal 700 meters long. Team A builds 60 meters every day, and Team B builds 20 meters less than Team A every day. How many days does it take to complete the combined practice?
甲、乙两队合修一条长700米的水渠，甲队每天修60米，乙队每天修的比甲队少修20米．合修几天可以修完？
<gadget id="calculator">60 - 20</gadget>
<output>40</output>

<gadget id="calculator">40 + 60</gadget>
<output>100</output>

<gadget id="calculator">700 / 100</gadget>
<output>7</output>

<result>7</result>