There are 30 members in the chorus, among which girls account for 3/5 of the chorus, how many boys are there?
合唱队有30人，其中女生占合唱队人数的(3/5)，男生有多少人．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">30 * (3/5)</gadget>
<output>18</output>

<gadget id="calculator">30 - 18</gadget>
<output>12</output>

<result>12</result>