use tabular anlysis (superposition) to solve

In a reverted epicyclic gear train, arm A carries two gears 1 and 2 at centre of rotation Ol and a compound gear 3 and 4 at the centre of rotation O2. The gear 1 meshes with gear 4 and gear 2 meshes with gear 3,Z1=75,Z2+30 and Z3=90. Find the speed and direction of gear 2 when gear 1 is fixed and arm makes 120rpm clockwise. Assume all gears to be of same module