A 20-cm-radius ball is uniformly charged to 75nc what is

Question

Solve the all parts of following problem:

Problem: A 20-cm-radius ball is uniformly charged to 75nC.

Part A: What is the ball's uniform charge density (C/m³)?

Part B: How much charge is enclosed by spheres of radii 5, 10, and 20 cm? The answer should be in nC?

Part C: What is the electric field strength at points 5, 10, and 20 cm from the center? The answer should be in N/C?

Please explain how you came to your conclusion.