51 The number of boys accounts for 55% of the whole class, and the number of girls accounts for the number of the whole class.
五1男生人数占全班人数的55%，女生人数占全班人数的多少．
<gadget id="calculator">55 / 100</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">1 - (11/20)</gadget>
<output>9/20 = around 0.45</output>

<result>9/20 = around 0.45</result>