# find total charge of three concentric spherical conductors

The potentials of three concentric spherical conductors of radii a,b,c such that a<b<c are held at the values $\phi=0,V, 0.$
Solve the potential problem by assuming $\phi=A+\frac{B}{r} \ \ \ \ and \ \ \ \phi= C+\frac{D}{r}$ for a<r<b and b<r<c.