For a certain product, the ratio of unqualified to qualified is 1:9, what is the qualified rate of the product?
某产品，不合格与合格的个数比是1：9，产品的合格率是多少．
<gadget id="calculator">1 + 9</gadget>
<output>10</output>

<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

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

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

<result>9/10 = around 0.9</result>