Xinxin Elementary School has 30 people participating in the dance interest group, which is an increase (1/5) from last year. How many people participated in the dance interest group last year? What is the correct column
鑫鑫小学有30人参加舞蹈兴趣小组，比去年增加了(1/5)，去年有多少人参加舞蹈兴趣小组？正确列式是多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">30 / (6/5)</gadget>
<output>25</output>

<result>25</result>