A 20-cm-radius ball is uniformly charge to 80nC

A 20-cm-radius ball is uniformly charge to 80nC. (26=4+5+5+6+6 points)         

1. What is the ball's volume charge density?                    
2. How much charge is enclosed by spheres of radii 5, 10 and 20 cm?                    
3. What is the electric field strength at points 5, 10, 20, 25 and 35 cm from the center?         
4. Draw the graph of the charge enclosed, Q_encl with the distance r from the center of the sphere for 0<r<35 cm.         
5. Draw the graph of the electric field, E(r) with the distance r from the center of the sphere for 0<r<35 cm.