$\overrightarrow A = 2\hat i + \hat j,\,B = 3\hat j - \hat k$ and $\overrightarrow C = 6\hat i - 2\hat k$.Value of $\overrightarrow A - 2\overrightarrow B + 3\overrightarrow C $ would be
With respect to a rectangular cartesian coordinate system, three vectors are expressed as
$\vec a = 4\hat i - \hat j$, $\vec b = - 3\hat i + 2\hat j$ and $\vec c = - \hat k$
where $\hat i,\,\hat j,\,\hat k$ are unit vectors, along the $X, Y $ and $Z-$axis respectively. The unit vectors $\hat r$ along the direction of sum of these vector is