factory draws 500 pieces from a batch of products. After inspection, 10 pieces are unqualified. What is the pass rate of this batch of products?
一个工厂从一批产品中抽出500件，经检验，有10件不合格，这批产品的合格率是多少．
<gadget id="calculator">500 - 10</gadget>
<output>490</output>

<gadget id="calculator">490 / 500</gadget>
<output>49/50 = around 0.98</output>

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

<gadget id="calculator">(49/50) * 1</gadget>
<output>49/50 = around 0.98</output>

<result>49/50 = around 0.98</result>