The students are doing radio exercises. There are 15 people standing in each row, and 12 rows. If there are 18 people standing in each row, how many rows should they stand? (Solve with ratio)
同学们做广播操，每行站15人，站了12行，如果每行站18人，要站多少行？(用比例解)
<gadget id="calculator">15 * 12</gadget>
<output>180</output>

<gadget id="calculator">180 / 18</gadget>
<output>10</output>

<result>10</result>