In a ratio, the product of two outer terms is the smallest composite number, one of which is 2.5, and what is the other inner term.
在一个比例里，两个外项的积是最小的合数，其中一个内项是2.5，另一个内项是多少．
<gadget id="calculator">4 / 2.5</gadget>
<output>1.6</output>

<result>1.6</result>