There are 120 willows in the garden. The number of willows is equal to that of poplars (5/9), and the number of poplars is equal to that of pine trees (4/15). How many pine trees are there?
园艺场有120棵柳树，柳树的棵数是杨树的(5/9)，杨树的棵数是松树的(4/15)，松树有多少棵？
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">4 / 15</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">120 / (5/9) / (4/15)</gadget>
<output>810</output>

<result>810</result>