There is a fraction. If 1 is added to the numerator and denominator, then the fraction becomes (1/2). If 1 is subtracted from both the numerator and denominator, then the fraction becomes (2/5). Find this fraction.
有一个分数，如果分子和分母都加上1，那么分数就变为(1/2)，如果分子和分母都减去1，那么分数就变为(2/5)，求这个分数．
<gadget id="calculator">5 / 11</gadget>
<output>5/11 = around 0.454545</output>

<result>5/11 = around 0.454545</result>