For a fraction, the numerator is 20 less than the denominator, and the fraction is (7/12), what is the original fraction?
一个分数，分子比分母少20，约分后是(7/12)，原分数是多少．
<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<result>7/12 = around 0.583333</result>