1. The problem statement, all variables and given/known data A particle carrying charge +q is placed at the center of a thick-walled conducting shell that has inner radius R and outer radius 2R and carries charge −3q. A thin-walled conducting shell of radius 5R carries charge +3q and is concentric with the thick-walled shell. Define V = 0 at infinity. Part A Calculate all distances from the particle at which the electrostatic potential is zero. Check all that apply. Check all that apply. r=10/3R r=11/5R r=5/6R r=5/7R 2. Relevant equations V=kQ/r 3. The attempt at a solution 0 = 1Q/R - 3Q/2R + 3Q/5R 0 = Q/10R 1/10th R is not in any of the solutions. I wonder what I'm doing wrong?