A circular pond has a circumference of 150 meters and a tree is planted every 3 meters. How many saplings are needed.
一个圆形池塘，它的周长是150米，每隔3米栽种一棵树．共需树苗多少株．
<gadget id="calculator">150 / 3</gadget>
<output>50</output>

<result>50</result>