The school chorus team participated in the "June 1st Celebration" cultural performance, standing in three rows with 20 people in each row. The number of boys in the first row is the same as that of girls in the second row, and 40% of the third row is girls. How many girls are there in the chorus?
学校合唱队参加"庆六一"文艺汇演，站成三排，每排20人．第一排男生与第二排女生人数同样多，第三排40%是女生．合唱队一共有女生多少人．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">20 * (2/5)</gadget>
<output>8</output>

<gadget id="calculator">20 + 8</gadget>
<output>28</output>

<result>28</result>