A cylinder with rotational inertia I1 = 3.0 kg · m2 rotates clockwise about a vertical axis through its center with angular speed ω1 = 5.4 rad/s. A second cylinder with rotational inertia I2 = 1.3 kg · m2 rotates counterclockwise about the same axis with angular speed ω2 = 6.4 rad/s. If the cylinders couple so they have the same rotational axis, what is the angular speed of the combination (in rad/s)?