If six points charges are distributed on a balloon encased within a cube,in such a manner that the points charges appear like dots on a die and if each point charge has a value of -q for its charge, and the radius of the

Question

balloon is R, what is the magnitude of the NET Electric Field, E, at the
location of each point charges, due to the other five? Your answer may only be
in terms of q, R, π, k, and ε0