Answer
72 cubic units.
Work Step by Step
The volume of the parallelepiped is given as:
$\textbf{u}\cdot(\textbf{v}\times\textbf{w})$
= det $\begin{pmatrix}u\\v\\w\end{pmatrix}$
$=\begin{vmatrix}1&0&4\\1&3&1\\-4&2&6\end{vmatrix}$
$=1(3\times6-2\times1)-0+4(1\times2-(-4\times3)=72 $
