1. The problem statement, all variables and given/known data The figure is a section of a conducting rod of radius R1 = 1.60 mm and length L = 11.30 m inside a thin-walled coaxial conducting cylindrical shell of radius R2 = 10.5R1 and the (same) length L. The net charge on the rod is Q1 = +3.67 × 10-12 C; that on the shell is Q2 = -2.04Q1. What is the charge on the interior and exterior surface of the shell? Picture inserted below. 2. Relevant equations I have no idea. 3. The attempt at a solution I don't even know how to start this. I know the answer of the charge on the exterior is the sum of Q1 and Q2, but I don't know how where the answer came from.