3. Girls in class 1 account for 4/9 of the whole class, and how many boys account for the whole class.
三1班女生占全班人数的(4/9)，男生占全班人数的多少．
<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">1 - (4/9)</gadget>
<output>5/9 = around 0.555556</output>

<result>5/9 = around 0.555556</result>