Originally (1/5) of the sixth graders participated in the mathematics interest group, and later 2 students joined the mathematics interest group, the actual number of participants was the remaining number (1/3). How many students participated in the Mathematics Interest Group?
六年级原有(1/5)的人参加数学兴趣小组，后来又有2名同学参加数学兴趣小组，实际参加人数是剩下人数的(1/3)．原有多少同学参加数学兴趣小组？
<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>