Which of the following is at a distance of $\sqrt{10}$ from the point $(1, 2, 3)$?

The sum of the squares of the perpendicular distances of a point $(x, y, z)$ from the coordinate axes is $k$ times the square of the distance of the point from the origin. Then $k=$

The coordinates of a point which is equidistant from the points $(0, 0, 0), (a, 0, 0), (0, b, 0)$ and $(0, 0, c)$ are given by

Locate the following points in a three-dimensional Cartesian coordinate system:
$(i)$ $(1, -1, 3)$
$(ii)$ $(-1, 2, 4)$
$(iii)$ $(-2, -4, -7)$
$(iv)$ $(-4, 2, -5)$

Find the distance between the following pairs of points: $(2, 3, 5)$ and $(4, 3, 1)$. (in $\sqrt{5}$)

If the centroid of the tetrahedron $OABC$,where $O$ is the origin $(0, 0, 0)$ and $A, B, C$ are given by $(a, 2, 3)$,$(1, b, 2)$,and $(2, 1, c)$ respectively,is $(1, 2, -1)$,then the distance of point $P(a, b, c)$ from the origin is equal to: