The students line up to do exercises, and the students who are ranked in front of Wang Xin account for 2/5 of the total. Counting from front to back, Wang Xin is ranked 7th. Then, the students who are ranked behind Wang Xin account for 2/5 of the total. What percentage?
同学们排成一队做操，排在王新前面的同学占总数的(2/5)，从前往后数，王新排在第7个，那么，排在王新后面的同学占总数的几分之几？
<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">6 / (2/5)</gadget>
<output>15</output>

<gadget id="calculator">15 - 7</gadget>
<output>8</output>

<gadget id="calculator">8 / 15</gadget>
<output>8/15 = around 0.533333</output>

<result>8/15 = around 0.533333</result>