Three concentric conducting spherical shells of radii r 2r 3r

A thin spherical shell with radius R1 = 1.00cm is concentric with a larger thin spherical shell with radius 5.00cm .Both shells are made of insulating material. The smaller shell has charge q1=+6.00nC distributed uniformly over its surface, and the larger shell has charge q2=?9.00nC distributed uniformly over its surface. Two concentric, spherical, conducting shells are arranged as shown. The inner shell has a charge 3Q, thickness R/2, and outside radius R. The outer sphere has a charge −Q, outside radius radius 3R, and thickness R.-Q R/2 R 2R 3R +3Q Answer the following questions: 3. What is the electric flux out of a concentric Gaussian sphere of radius 1.5R?