If the number of boys in a class is 4/5 of the number of girls, then how many girls account for the total number of students in the class?
某班男生人数是女生人数的(4/5)，那么女生人数占全班总人数的多少．
<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

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