Solve the all parts of following problem given below:

Problem: The electric field at point P just outside the outer surface of a hollow spherical conductor of inner radius 10 cm and outer radius 29 cm has magnitude 457 N/C and is directed outward. When an unknown point charge Q is introduced into the center of the sphere, the electric field at P is still directed outward but is now 198 N/C.

Part A: What was the net charge enclosed by the outer surface before Q was introduced?

Part B: What is charge Q? After Q is introduced?

Part C: What is the charge on the inner surface of the conductor?

Part D: What is the charge on the outer surface of the conductor?

Explanation and formulas needed for best answer!