Master Zhou processes a batch of parts. The ratio of the number of unqualified products to the number of qualified products is 1:9. What is the pass rate of this batch of products?
周师傅加工一批零件，不合格产品数与合格产品数的比是1：9，这批产品的合格率是多少
<gadget id="calculator">9 + 1</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>