The original willow trees on the People's Highway accounted for 2/5 of the total number of trees, and 50 willow trees were planted this year. In this way, willow trees account for (5/11) of the total number of trees. How many trees were there in the park?
人民公路原有柳树是树木总数的(2/5)，今年又栽种了50棵柳树．这样柳树就占了全部棵数的(5/11)，公园原来有多少棵树？
<gadget id="calculator">5 / 11</gadget>
<output>5/11 = around 0.454545</output>

<gadget id="calculator">50 * (5/11)</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">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>