The value of k such that x−41=y−21=z−k2 lies in the plane 2x−4y+z=7 is
7
-7
No real value
4
As the line x−41=y−21=z−k2 lies in the plane 2x−4y+z=7
the point (4,2,k) through which it passes must also lie on the given plane, and hence 2×4−4×2+k=7 or k=7.