For 2:5, if the former term of the ratio is increased by 6, how much must the latter term be increased to keep the ratio constant?
对于2：5，若比的前项增加6，要使比值不变，比的后项需要增加多少
<gadget id="calculator">20 - 5</gadget>
<output>15</output>

<result>15</result>