After the activity class, the squad leader sent (1/5) of the whole class to clean the cleaning area, and another 2 students took the initiative to participate. At this time, the number of people participating in cleaning is equivalent to (1/3) of the number of people not participating in cleaning. How many students are there in this class?
活动课后，班长派全班同学的(1/5)去打扫清洁区，另外又有2名同学主动参加．这时，参加扫除的人数相当于未参加扫除人数的(1/3)．这个班共有学生多少人？
<gadget id="calculator">3 / 1</gadget>
<output>3</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">2 / (1/20)</gadget>
<output>40</output>

<result>40</result>