There is a kind of commodity, the purchase price of store A is 10% cheaper than that of store B, store A is priced at 20% profit, and store B is priced at 15% profit, the price of store A is 11.2 yuan cheaper than that of store B. How much is the purchase price of store A?
有一种商品，甲店进价比乙店进价便宜10%，甲店按20%的利润定价，乙店按15%的利润定价，甲店的定价比乙店的定价便宜11.2元．则甲店的进价是多少元
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/10) * (1/5)</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">(1/50) - 1 - (1/5)</gadget>
<output>-59/50 = around -1.18</output>

<gadget id="calculator">1 + (3/20) + (1/10) + (-59/50)</gadget>
<output>7/100 = around 0.07</output>

<gadget id="calculator">11.2 / (7/100)</gadget>
<output>160</output>

<gadget id="calculator">(9/10) * 160</gadget>
<output>144</output>

<result>144</result>