The original number of willows in Jiefang Park is 40% of the total number of trees in the park, and another 50 willows were planted this year. At this time, the number of willow trees accounted for the total number of trees (5/11). How many trees were there in Jiefang Park?
解放公园里原有柳树棵数是公园里树木总棵树的40%，今年又种了50棵柳树．这时柳树棵数就占总棵数的(5/11)，解放公园里原来有树木多少棵？
<gadget id="calculator">250 / 11</gadget>
<output>250/11 = around 22.727273</output>

<gadget id="calculator">50 - (250/11)</gadget>
<output>300/11 = around 27.272727</output>

<gadget id="calculator">5 / 11</gadget>
<output>5/11 = around 0.454545</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(5/11) - (2/5)</gadget>
<output>3/55 = around 0.054545</output>

<gadget id="calculator">(300/11) / (3/55)</gadget>
<output>500</output>

<result>500</result>