The fourth grade students participate in the group gymnastics performance. There are 20 people standing in each row, exactly 45 rows. If it is changed to 25 people in each row, how many rows can they stand? (Solve using ratio method)
四年级学生参加团体操表演，每行站20人，正好站45行，如果改为每行站25人，可以站多少行？(用比例方法解答)
<gadget id="calculator">20 * 45</gadget>
<output>900</output>

<gadget id="calculator">900 / 25</gadget>
<output>36</output>

<result>36</result>