There are 15 boys, less than girls (1/6), how many girls are there?
男生15人，比女生少(1/6)，女生有多少人．
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/6)</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">15 / (5/6)</gadget>
<output>18</output>

<result>18</result>