Help

A sphere of radius R = 0.275 m and uniform charge density -755 nC/m' lies at the center of a spherical, conducting shell of inner and outer radii 3.50R and 4.00R, respectively. If the conducting shell carries a total charge of O = -38.1 nC, find the magnitude of the electric field at the given radial distances from the center of the charge distribution. 0.360R: N/C O R 3.65 R: N/C 3.50R 4.00R 3.20R: N/C 5.30R: N/C