Cylindrical shells and charges?

A thin cylindrical shell of radius R1=6.5 cm is surrounded by a second cylindrical shell of radius R2=9.0 cm. Both cylinders are 5.0 m long and the inner one carries a total charge Q1=-0.88 uC and the outer one Q2=+1.56uC. For points far from the ends of the cylinders, determine the electric field at a radial distance r from the central axis of (a) 3.0 cm, (b) 7.0 cm, and (c) 12.0 cm.