Gausse's Law Question

 A very long charged conducting wire, of radius a = 12.0 cm, is enclosed by a concentric, conducting neutral hollow cylinder, as shown in the diagram above. The electric field is E⃗ 1�→1 = 1.60×104 N/C at b = 18.0 cm from the center of the wire and in the direction shown. What is the magnitude of the electric field at point P, a distance of c= 42.0 cm from the center of the wire?