If girls make up 45% of the class, what percentage of boys are in the class
如果女生占全班人数的45%，那么男生人数占全班人数的多少
<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 - (9/20)</gadget>
<output>11/20 = around 0.55</output>

<result>11/20 = around 0.55</result>