Answer
(a )$0$
(b) Yes.
Work Step by Step
(a) Given the three vectors, first calculate the cross product of the two vectors: $\vec v\times\vec w
=\langle (2\times10-1\times8), (1\times0+3\times10), (-3\times8-2\times0) \rangle
=\langle 12, 30, -24 \rangle$. Next we calculate the scalar triple product as $\vec u\cdot(\vec v\times\vec w)
=1\times12+2\times30-3\times24=0$
(b) As the scalar triple product is zero, we conclude that these vectors are coplanar.
