A wheat field of 120 hectares was harvested 3.5 hours ago by a harvester (7/20). According to this speed, how many hours will it take to harvest this field? (Answer with proportional knowledge)
一块120公顷的麦地，一台收割机前3.5小时收割了(7/20)，按照这样的速度，这块地要多少小时才能收割完？(用比例知识解答)
<gadget id="calculator">7 / 20</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">3.5 / (7/20)</gadget>
<output>10</output>

<result>10</result>