The school beautifies the campus and purchased a batch of rose flowers. If 30 trees are planted in each row, 25 rows can be planted. If it is changed to 15 trees in each row, how many rows can be planted?
学校美化校园，购进一批月季花，如果每行栽30棵，可以栽25行，如果改栽成每行15棵，可以栽多少行？
<gadget id="calculator">25 / 15</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">30 * (5/3)</gadget>
<output>50</output>

<result>50</result>