Two concentric spherical conducting shells have radii = 2.7…

Two concentric spherical conducting shells have radii = 2.7 cm and = 13.7 cm as shown in the drawing. The shells have a finite thickness that is much less than either radius. The inner and outer shells carry net charges = 2.3 nC and = 2.8 nC respectively. What is the electric field strength at a distance 5.1 cm from the center of the sphere?