If the purchase price of a commodity is reduced by 10% while the selling price remains the same, the gross profit rate can be increased by 2%. What is the gross profit rate of this commodity? (Gross profit margin = (selling price - purchase price)/purchase price * 100%)
某种商品，如果进价降低10%，售价不变，那么毛利率可增加2%，原来这种商品的毛利率是多少．(毛利率=(售价-进价)/进价*100%)
<gadget id="calculator">1.02 - 0.9</gadget>
<output>0.12</output>

<gadget id="calculator">1.02 - 1</gadget>
<output>0.02</output>

<gadget id="calculator">0.12 / 0.02</gadget>
<output>6</output>

<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">5 / 1</gadget>
<output>5</output>

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

<gadget id="calculator">5 * 1</gadget>
<output>5</output>

<result>5</result>