There are 50 people in the class doing a math problem, and 10 get it wrong. What is the error rate of this problem?
一道数学题全班有50人做，10个做错，这道题的错误率是多少．
<gadget id="calculator">10 / 50</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">(1/5) * 1</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>