There are 120 willow trees in the forest park, twice as many as poplar trees, and three times as many pine trees as poplar trees. How many pine trees are there in the forest park?
森林公园里有柳树120棵，是杨树棵树的2倍，而松树棵树是杨树的3倍，森林公园里有松树多少棵？
<gadget id="calculator">120 / 2</gadget>
<output>60</output>

<gadget id="calculator">60 * 3</gadget>
<output>180</output>

<result>180</result>