In the half-term exam, six (2, 40) passed the exam, and 10 failed the exam. What is the passing rate of their class?
半期考试中，六(2,40人考及格，10没考及格，他们班及格率是多少．
<gadget id="calculator">40 + 10</gadget>
<output>50</output>

<gadget id="calculator">40 / 50</gadget>
<output>4/5 = around 0.8</output>

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

<gadget id="calculator">(4/5) * 1</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>