If a product is sold at the original price, it can make a profit of 25%, but if it is sold at a 30% discount, it will lose 30 yuan. So how much is the purchase price of this product?
一件商品如果按原价出售可以盈利25%，如果降价30%出售，则要亏本30元，那么这件产品的进价是多少元？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * (3/10)</gadget>
<output>3/40 = around 0.075</output>

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

<gadget id="calculator">(3/10) + (3/40) + (-1/4)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">30 / (1/8)</gadget>
<output>240</output>

<result>240</result>