Boys account for (7/12) of the total number, and girls account for ((())/(())).
男生占总人数的(7/12)，女生占男生人数的((())/(()))．
<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">1 - (7/12)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">(5/12) / (7/12)</gadget>
<output>5/7 = around 0.714286</output>

<result>5/7 = around 0.714286</result>