Among the students who participated in various sports interest groups in our school last year, 20% were girls. In order to welcome the 2008 Olympic Games, the number of students participating in various sports interest groups increased (1/5) this year, and the number of girls accounted for (1/4) of the total number. So how many percent increase in the number of girls participating in various sports interest groups this year compared to last year?
我校去年参加各种体育兴趣小组的同学中，20%是女生．为迎接2008年奥运会，今年参加各种体育兴趣小组的学生增加了(1/5)，其中女生人数占总人数的(1/4)．那么今年女生参加各种体育兴趣小组的人数比去年增加百分之多少．
<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">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(6/5) * (1/4)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">20 / 100</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">(1/10) / (1/5)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>