If (a, b, c) is the image of the point (1, 2, -3) in

the line $${{x + 1} \over 2} = {{y - 3} \over { - 2}} = {z \over { - 1}}$$, then a + b + c is :

The distance of the point (1, –2, 3) from
the plane x – y + z = 5 measured parallel to
the line $${x \over 2} = {y \over 3} = {z \over { - 6}}$$ is:

The plane which bisects the line joining, the points (4, –2, 3) and (2, 4, –1) at right angles also passes through the point:

The foot of the perpendicular drawn from the point (4, 2, 3) to the line joining the points (1, –2, 3) and (1, 1, 0) lies on the plane :