A batch of fruit weighs 500 kilograms, 40% of it is sold, and 40% is shipped in. What is the weight of the fruit at this time?
一批水果重500千克，卖出40%，又运进40%，这时水果重多少千克．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 + (2/5)</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">500 * (3/5) * (7/5)</gadget>
<output>420</output>

<result>420</result>