Boys in Class 6 and 7 account for 60% of the class, and how many girls account for the whole class?
六7班男生占了全班人数的60%，女生占全班人数的多少
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>