A batch of parts is produced, and the ratio of qualified parts to unqualified parts is 9:1. What is the pass rate of this batch of parts?
生产一批零件，合格零件与不合格零件的比是9：1，这批零件的合格率是多少．
<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>