Among the students who participated in the elementary school mathematics olympiad in a certain area last year, students from ethnic minorities accounted for one-fifth. This year, the number of students participating in the district has increased by 40%, so students from ethnic minorities account for a quarter of the total number. Compared with last year, how much has the number of ethnic minority students participating this year increased?
去年某地区参加小学数学奥林匹克的学生中，少数民族的同学占五分之一．今年全区参赛的学生增加了40%，这样少数民族的同学就占总人数的四分之一．与去年相比较，今年少数民族学生参赛人数增加了多少．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 + (2/5)</gadget>
<output>7/5 = around 1.4</output>

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

<gadget id="calculator">(7/5) * (1/4)</gadget>
<output>7/20 = around 0.35</output>

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

<gadget id="calculator">(7/20) - (1/5)</gadget>
<output>3/20 = around 0.15</output>

<result>3/20 = around 0.15</result>