Complete Question
Two spherical shells have a common center. A -1.6 x 10-6 C charge is spread uniformly over the inner shell, which has a radius of 0.030 m. A +5.1 x 10-6 C charge is spread uniformly over the outer shell, which has a radius of 0.15 m.What are the magnitude and direction of the electric field at a distance 43.5 mm from the center of the shells.
Answer:
The magnitude is

The direction is radially inward toward the center
Step-by-step explanation:
From the question we are told that
The charge on the inner shell is

The radius of the inner shell is

The charge on the outer shell is

The radius of the outer shell is

The distance considered is

Generally the electric field at the position considered is mathematically represented as

Here
is the charge which is enclosed by the distance considered which in this case is the charge on the inner shell
So

Hence

=>

The negative sign is show that the direction of the field is radially inward toward the center