Given the fraction (5/12), if 7 is added to the numerator, how much should be added to the denominator, the original fraction becomes (3/8).
已知分数(5/12)，如果分子加上7，分母应加上多少后，原分数就变为(3/8)．
<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<gadget id="calculator">32 - 12</gadget>
<output>20</output>

<result>20</result>