The ratio of boys to girls in a class is 7:8, how many boys account for the whole class.
某班男、女生人数的比是7：8，男生占全班人数的多少．
<gadget id="calculator">7 + 8</gadget>
<output>15</output>

<gadget id="calculator">7 / 15</gadget>
<output>7/15 = around 0.466667</output>

<result>7/15 = around 0.466667</result>