The simplest ratio of the numerator and denominator of a fraction is 1:2. After adding 12 to the numerator and denominator at the same time, the reduced fraction is (3/5). Find this fraction.
一个分数的分子、分母的最简比是1：2，分子、分母同时加上12以后，约分后的最简分数为(3/5)，求这个分数．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>