The supermarket completed the sales plan of the current month (1/5) in the first ten days of the month, completed the sales plan of the current month (7/10) in the middle ten days of the month, and completed (1/4) the sales plan of the current month in the last ten days of the month. What percentage of the plan for the month has actually been overfulfilled this month?
超市上旬完成当月销售计划的(1/5)，中旬完成当月销售计划的(7/10)，下旬完成当月计划的(1/4)．这个月实际超额完成当月计划的几分之几？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) - 1</gadget>
<output>-3/4 = around -0.75</output>

<gadget id="calculator">(1/5) + (7/10) + (-3/4)</gadget>
<output>3/20 = around 0.15</output>

<result>3/20 = around 0.15</result>