If the purchase price of a certain commodity is reduced by 10%, if the selling price remains unchanged, then its profit margin will increase by 15 percentage points. What is the original rate of profit?
某种商品的进价降低10%，如果售价不变，那么其利润率将增加15个百分点．则原来的利润率是多少．
<gadget id="calculator">1.35 - 1</gadget>
<output>0.35</output>

<gadget id="calculator">0.35 / 1</gadget>
<output>0.35</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">0.35 * 1</gadget>
<output>0.35</output>

<result>0.35</result>