physics question (please show work)

Question

You have two identical metal spheres (identical aside from their net charges, that is). Sphere A has a net charge of +11.0 nanocoulombs, while sphere B has a net charge of -3.00 nanocoulombs. The spheres are touched together briefly, and then separated. During this process, no net charge is removed from or added to the two-sphere system. After the spheres are separated, what is the net charge on sphere B?

_______ nC

Answer 1

If the spheres are identical, the problem is simply a matter of adding the charge and distributing it evenly between the spheres. Each sphere gets (11-3 nC)/2 = 4 nC

If the spheres had been different they would have had to reach the same voltage (kQ/r) at equilibrium