The unit vector in the direction of the vector $(1, 0, 0)$ is $.......$

If $|\vec{f}|=10, |\vec{g}|=14$ and $|\vec{f}-\vec{g}|=15$,then $|\vec{f}+\vec{g}|=$

Find the position vector of a point $R$ which divides the line joining two points $P$ and $Q$ whose position vectors are $\hat{i}+2 \hat{j}-\hat{k}$ and $-\hat{i}+\hat{j}+\hat{k}$ respectively,in the ratio $2: 1$ externally.

If $a, b, c$ are three linearly independent vectors and there exists a non-zero scalar triad $(l, m, n)$ such that $l(3a + 2b + c) + m(2a + 2b + 3c) + n(a + 2b + 5c) = 0$, then:

In $\triangle OAC$,if $B$ is the mid-point of side $AC$ and $\vec{OA}=\vec{a}, \vec{OB}=\vec{b}$,then $\vec{OC}$ is equal to

Classify the following measure as a scalar or a vector:
$40^{o}$