There are 3 more boys in the chorus group than girls (2/3), 15 boys, how many girls are there?
合唱小组的男生比女生的(2/3)多3人，男生15人，女生有多少人？
<gadget id="calculator">15 - 3</gadget>
<output>12</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">12 / (2/3)</gadget>
<output>18</output>

<result>18</result>