The food company buys a batch of oranges, sells all (2/5) on the first day, sells the rest (1/2) on the second day, sells less (1/3) than the first day on the third day, At this time, there are 50 kilograms of oranges left. How many kilograms of oranges did the food company buy? (column solution)
食品公司进了一批桔子，第一天卖出全部的(2/5)，第二天卖出剩下的(1/2)，第三天比第一天少卖(1/3)，这时还剩50公斤，食品公司共进了多少公斤桔子？(列式解答)
<gadget id="calculator">2 / 5</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</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(3/5) * (1/2)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/5) * (2/3)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">1 - (2/5) - (3/10) - (4/15)</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">50 / (1/30)</gadget>
<output>1_500</output>

<result>1_500</result>