Willow trees are 350 fewer than apple trees, and the number of apple trees is 15 times that of willow trees. How many willow trees are there?
柳树比苹果树少350棵，苹果树的棵数是柳树的15倍，问柳树有多少棵？
<gadget id="calculator">15 - 1</gadget>
<output>14</output>

<gadget id="calculator">350 / 14</gadget>
<output>25</output>

<result>25</result>