A performance phalanx is performing a parade exercise. If 20 people stand in each row, they can stand in 18 rows. If 30 people stand in each row, how many rows can they stand in?
某表演方阵进行列队演习，如果每排站20人，可以站成18排．如果每排站30人，可以站成多少排？
<gadget id="calculator">18 / 30</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">20 * (3/5)</gadget>
<output>12</output>

<result>12</result>