A solid conducting sphere with radius R that carries positive charge Q is concentric with a very

Question:

A solid conducting sphere with radius R that carries positive charge Q is concentric with a very thin insulating shell of radius 2R that also carries charge Q. The charge Q is distributed uniformly over the insulating shell.
(a) Find the electric field (magnitude and direction) in each of the regions 0 < r < R, R < r < 2R, and r > 2R.
(b) Graph the electric-field magnitude as a function of r.