batch of fruit is sold on the first day (2/7), and after selling 20 kg more than the first day on the second day, there are still 40 kg left. How many kg of this batch of fruit are there?
一批水果，第一天卖出(2/7)，第二天比第一天多卖出20千克后，还剩40千克，这批水果原有多少千克？
<gadget id="calculator">20 + 40</gadget>
<output>60</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(2/7) + (2/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">1 - (4/7)</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">60 / (3/7)</gadget>
<output>140</output>

<result>140</result>