Need help with this dynamics qeuestion please only answer if confident with result

Case $1$: When arm D is stationary. $(3$ marks$)$ Case $2$: When Sun gear is stationary

Calculate the output speed and direction. $(2$ marks$)$

Speed ratio: $R_S=\frac{{}_f}{{}_d}=\frac{N_f}{N_d}=\frac{D_d}{D_f}=\frac{T_d}{T_f}$

$P_i=M_{t_i}{}_i$

Using tabular method:

An epicyclic gearbox $-$ Type $1$ Henriot has the following elements:

See above figure for the gear box arrangement

Output shaft is attached to ring gear A and has $50$ teeth.

Gear A drives planet gear B$,$ which has $10$ teeth

Gear B is meshed with Sun gear C which is fixed to input shaft

Gear $C$ is attached to the Input shaft which is rotating at $+300$ rpm

Is the meshing right considering the rule $??$ comment true or false with calculations. $(1$ marks$)$