Answer
20 cubic units.
Work Step by Step
The volume of the parallelepiped is given as:
$\textbf{u}\cdot(\textbf{v}\times\textbf{w})$
= det $\begin{pmatrix}u\\v\\w\end{pmatrix}$
$=\begin{vmatrix}2&2&1\\1&0&3\\0&-4&0\end{vmatrix}$
$=0-[-4(2\times3-1\times1)]+0$
(As there are two zeros in the third row, evaluation of the determinant by the expansion along the third row is easy.)
=20 cubic units.
