In a school voluntary labor, 20 people were arranged to dig soil and 28 people to lift it. It is observed that it takes 2 people to carry the soil dug by 1 person in time, so how many people should be transferred from the diggers to the soil-lifting team.
在一次学校义务劳动中，安排20人挖土，28人抬土．据观察发现1人挖出的土，需2人才能及时抬走，那么应从挖土人员中抽调多少人人到抬土队伍中来．
<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">48 / 3</gadget>
<output>16</output>

<gadget id="calculator">20 - 16</gadget>
<output>4</output>

<result>4</result>