How many different spheres of radius $r$ can be drawn which touch all the three coordinate axes?

The shortest distance from the plane $12x + 4y + 3z = 327$ to the sphere $x^2 + y^2 + z^2 + 4x - 2y - 6z = 155$ is

$A$ plane passes through a fixed point $(p, q, r)$ and cuts the axes at $A, B, C$. Then the locus of the centre of the sphere $OABC$ is

The equation of the sphere passing through the points $(1,0,0), (0,1,0)$ and $(1,1,1)$ and having the smallest radius is:

The radius of the sphere $x^2+y^2+z^2=12x+4y+3z$ is

If the volume of a sphere increases by $72.8 \%$,then its surface area increases by $... \%$