In the ratio of 4:10, if its former term is added by 6, how much should its latter term be added to keep its ratio unchanged.
在4：10的比例中，若它的前项加6，要使它的比值不变，它的后项应加多少．
<gadget id="calculator">25 - 10</gadget>
<output>15</output>

<result>15</result>