In the figure a solid sphere of radius a = 3.70 cm is concentric with a spherical conducting shell of inner radius b = 2.00a and outer radius c = 2.40a. The sphere has a net uniform charge q₁ = +7.56 fC; the shell has a net charge q₂ = -q₁. What is the magnitude of the electric field at radial distances (a) r = 0 cm, (b) r = a/2.00, (c) r = a, (d) r = 1.50a, (e) r = 2.30a, and (f) r = 3.50a? What is the net charge on the (g) inner and (h) outer surface of the shell?