For a commodity, the purchase price of commodity A is 10% cheaper than that of commodity B. Store A sets the price at 30% profit, and store B sets the price at 25% profit. As a result, store A is 40 yuan cheaper than store B. How much is the purchase price of store A?
一种商品，甲商品比乙商品的进货价便宜10%，甲商店按30%的利润定价，乙商店按25%的利润定价，结果甲店比乙店便宜40元．甲店的进货价是多少元？
<gadget id="calculator">1.25 - 1.17</gadget>
<output>0.08</output>

<gadget id="calculator">40 / 0.08</gadget>
<output>500</output>

<gadget id="calculator">500 * 0.9</gadget>
<output>450</output>

<result>450</result>