Some charged particles are suspended inside a hollow metal object by supports made of a material that is an electrical insulator. The metal object has charge \(+q\) distributed over its outer surface and charge \(-2 q\) distributed over its inner surface.

(a) How much charge is suspended in the cavity?

(b) What is the charge on the object? (Hint for part \(b\) : What is the electric field a very large distance \(r\) from the center of the object?)