It is known that the product of two factors is 20.4, one of which is 4, and what is the other factor.
已知两个因数的积是20.4，其中一个因数是4，另一个因数是多少．
<gadget id="calculator">20.4 / 4</gadget>
<output>5.1</output>

<result>5.1</result>