Two concentric, conducting spherical shell are charged as shown in the figure (+

Two concentric, conducting spherical shell are charged as shown in the figure (+Q for the inner shell, +2Q for the outer shell). Using Gauss’s Law and the Charge Conservation principle, determine the charge on:
1)   Surface A (inner surface of the inner shell) [10 marks]
2)   Surface B (outer surface of the inner shell) [10 marks]
3)   Surface C (inner surface of the outer shell) [10 marks]
4)   Surface D (outer surface of the outer shell) [10 marks]
(Hint: what is the value of the electric field inside a conductor?)
If the outer radius of the outer shell is R = 15 cm, what is the electric field at a point P, 30 cm. from the outer edge? Write your answer as a function of Q. [10 marks]