Please give me only one solution without AI or chatbot.

A non-conducting charged sphere has a radius of R = 10 cm. Its center is located at the origin of the coordinate system. The charge density p is jnhcmcgenenesty distributed inside the sphere. It depends on the distance r to the center, but not on the angular coordinates. It applies [p(r)| = a/r2 with a = 10 C/m. a) Determine the total charge IQI of the ball. [3 points] b) Use the Gauss law to derive an expression for the electric field outside the ball. [2 points] c) At a distance d from the center of the ball, an electric field of strength E = -3 kV/m is measured. Determine the distance d. What is the sign of the charge of the ball? [2 points]