A batch of willow and peach trees are planted for greening the campus, and it is planned that willows will account for 40% of the total. After considering the landscape needs, we replaced 5 willow trees with 5 peach trees. At this time, the ratio of willow trees to peach trees is 3:7. How many willow and peach trees are planted in the school?
为绿化校园种植一批柳树和桃树，计划柳树占总棵数的40%．后考虑景观需要，又将5棵柳树换成了5棵桃树，这时柳树与桃树之比为3：7．学校共种植柳树和桃树多少棵？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">3 + 7</gadget>
<output>10</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(2/5) - (3/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">5 / (1/10)</gadget>
<output>50</output>

<result>50</result>