In the first half of the year, our county completed the annual tree planting task (2/5). After the tree planting in the second half year, it was found that the whole year would exceed the plan (1/20). What percentage of the annual tree planting task was completed in the second half of the year?
我县上半年完成全年植树任务的(2/5)，下半年植树后发现全年将比计划超额(1/20)，下半年完成全年植树任务的几分之几？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

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

<gadget id="calculator">(1/20) - (2/5)</gadget>
<output>-7/20 = around -0.35</output>

<gadget id="calculator">1 + (-7/20)</gadget>
<output>13/20 = around 0.65</output>

<result>13/20 = around 0.65</result>