$<2, 2, 2> = \ldots \ldots$

If $a = 3i - 2j + k$,$b = 2i - 4j - 3k$ and $c = -i + 2j + 2k$,then $a + b + c$ is

If $\hat{i}+2 \hat{j}+3 \hat{k}$ and $3 \hat{i}+2 \hat{j}+\hat{k}$ are sides of a parallelogram,then a unit vector parallel to one of the diagonals of the parallelogram is

If $\bar{x}$ is a non-zero vector and $k < 0, k \neq -1$,then $\frac{k \bar{x}}{|\bar{x}|}$ is $.........$

The unit vector $\vec{r}$ which satisfies $\vec{r} \times \vec{b} = \vec{r} \times \vec{c}$,where $\vec{b} = \hat{i} + 2\hat{j} + \hat{k}$ and $\vec{c} = 3\hat{i} + 2\hat{k}$,is:

The points whose position vectors are $2\hat{i}+3\hat{j}+4\hat{k}$, $3\hat{i}+4\hat{j}+2\hat{k}$, and $4\hat{i}+2\hat{j}+3\hat{k}$ are the vertices of