The ratio of a ratio is 5, if its former term is enlarged to 3 times of the original and the latter term remains unchanged, what is the ratio.
一个比的比值是5，若它的前项扩大到原来的3倍，后项不变，比值是多少．
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<result>15</result>