Clockwise rotation induces a negative angular momentum at right angles to the spinning disk, while anti-clockwise rotation induces a positive angular mementum. Angular momentum L=I⍵ where I=moment of inertia=mr²/2 for a solid disk, and m is its mass and r its radius.
⍵=30revs/sec=60π radians / sec.
For disk A, L=-9.6π and disk B, L=2.4π mks.
Combined ang momentum initially=-7.2π.
Combined moments of inertia=0.16+0.04=0.20.
If ⍵ is the final angular velocity: final AM=initial AM, 0.20⍵=-7.2π, ⍵=-36π=18 revs/s clockwise.