There is a fraction. After dividing this fraction by (2/7), the sum of the numerator and denominator is 71. It turns out that the sum of its numerator and denominator is 28. What is the fraction?
有一个分数，用这个分数除以(2/7)后，分子与分母的和是71，原来它的分子分母的和是28，这个分数是多少．
<gadget id="calculator">28 * 2</gadget>
<output>56</output>

<gadget id="calculator">71 - 56</gadget>
<output>15</output>

<gadget id="calculator">7 - 2</gadget>
<output>5</output>

<gadget id="calculator">15 / 5</gadget>
<output>3</output>

<gadget id="calculator">28 - 3</gadget>
<output>25</output>

<gadget id="calculator">15 / 5 / 25</gadget>
<output>3/25 = around 0.12</output>

<result>3/25 = around 0.12</result>