Add 6 to the numerator of (3/10), how much should be added to the denominator if the size of this fraction is to remain the same
(3/10)的分子加上6，如果要使这个分数的大小不变，分母应该加上多少
<gadget id="calculator">10 * 3</gadget>
<output>30</output>

<gadget id="calculator">30 - 10</gadget>
<output>20</output>

<result>20</result>