16. (6 points) If a rectangular prism has a length that is twice its width, and a width that is twice its height, and the sum of all its edges is 56, then the volume of this rectangular prism is $\qquad$ .
16. (6 points) If a rectangular prism has a length that is twice its width, and a width that is twice its height, and the sum of all its edges is 56, then the volume of this rectangular prism is $\qquad$ .

【Solution】Solution: The height of the rectangular prism is:
$$
\begin{array}{l}
56 \div 4 \div(1+2+4), \\
=14 \div 7, \\
=2,
\end{array}
$$

The width is: $2 \times 2=4$,
The length is: $4 \times 2=8$,
The volume is: $8 \times 4 \times 2=64$,
Answer: The volume of this rectangular prism is 64.
Therefore, the answer is: 64.