There is a class of prime numbers whose denominator and numerator are both greater than 10 and less than 30. So what is the fraction with the smallest difference from (1/2).
有一类分数的分母与分子都大于10小于30的质数．那么其中与(1/2)之差最小的分数是多少．
<gadget id="calculator">11 / 23</gadget>
<output>11/23 = around 0.478261</output>

<result>11/23 = around 0.478261</result>