wholesaler in a stationery store purchased a batch of mechanical pencils and sold them at a price increase of 40% for each mechanical pencil. When the wholesaler sold 500 mechanical pencils, it happened to recover all the costs. After all the pencils are sold at a reduced price, the total profit is 30%, and the remaining pencils are sold at a lower price.
某文具店批发商购进一批自动铅笔，按每支自动铅笔加价40%售出，当这个批发商售出500枝自动铅笔时，正好收回全部成本，由于市场环境发生变化，批发商把剩余铅笔降价全部售出后，共获利30%，剩余的铅笔是降多少售出的．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">500 * (7/5)</gadget>
<output>700</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">700 - 500</gadget>
<output>200</output>

<gadget id="calculator">(3/10) / 200</gadget>
<output>3/2_000 = around 0.0015</output>

<gadget id="calculator">700 * (3/2_000)</gadget>
<output>21/20 = around 1.05</output>

<gadget id="calculator">(2/5) - (21/20)</gadget>
<output>-13/20 = around -0.65</output>

<gadget id="calculator">1 + (-13/20)</gadget>
<output>7/20 = around 0.35</output>

<result>7/20 = around 0.35</result>