The product of the two inner terms of the ratio is 20, and one of the outer terms is the smallest composite number, then what is the other outer term.
比例的两内项之积为20，其中的一个外项是最小的合数，那么另一个外项是多少．
<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<result>5</result>