The original (1/5) students in a class participated in the general cleaning, and then 2 students participated in it. The actual number of participants was (1/3) of the rest. How many students originally participated in the general cleaning?
一班原有(1/5)的同学参加大扫除，后来又有2个同学参加，实际参加的人数是其余人数的(1/3)，原来有多少同学参加大扫除？
<gadget id="calculator">1 + 3</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>

<gadget id="calculator">40 * (1/5)</gadget>
<output>8</output>

<result>8</result>