A pond is 30 meters long, and a willow tree is planted every 2 meters around the pond. How many willow trees should be planted in total?
一个池塘周围长30米，在池塘四周每隔2米栽一棵柳树，一共要栽多少棵柳树．
<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<result>15</result>