3 tractors cultivate 60 mu of land in 5 hours. According to this calculation, how many hours will it take for 5 such tractors to cultivate 120 mu of land.
3台拖拉机5小时耕地60亩，照这样计算，5台这样的拖拉机，耕地120亩，需要多少小时．
<gadget id="calculator">60 / 3 / 5</gadget>
<output>4</output>

<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<gadget id="calculator">120 / 20</gadget>
<output>6</output>

<result>6</result>