The fourth grade students carry out dancing and singing competitions. The number of people participating in the competition accounts for 80% of the whole grade, among which those participating in dancing account for 30% of the number of participants, and those participating in singing account for 4/5 of the number of participants. 24 people. How many students are there in the fourth grade?
四年级学生开展跳舞和唱歌比赛，参加比赛的人数占全年级的80%，其中参加跳舞的占比赛人数的30%，唱歌的占参赛人数的(4/5)，两种比赛都参加的有24人．四年级共有学生多少人？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(4/5) - 1</gadget>
<output>-1/5 = around -0.2</output>

<gadget id="calculator">(3/10) + (-1/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">24 / (1/10) / (4/5)</gadget>
<output>300</output>

<result>300</result>