Two very large Non Conducting Plastic sheets each 10 Cm thick Electric Field

Two very large, nonconducting plastic sheets, each 10.0 cm thick, carry uniform charge densities σ1,σ2,σ3 and σ4 on their surfaces (the four surfaces are in the following order σ1,σ2,σ3 and σ4 going from left to right). These surface charge densities have the values σ1=−6,σ2=+5,σ3=+2 and σ4=+4

all in C/(m*m).

A) Use Gauss's law to find the magnitude of the electric field at the point A, 5.00 cm from the left face of the left-hand sheet.

B) Find the magnitude of the electric field at the point B, from the inner surface of the right-hand sheet.

C) Find the magnitude of the electric field at the point C, in the middle of the right-hand sheet.