Q 36. An epicyclic gear train is shown schematically in the adjacent figure
The sun gear 2 on the input shaft is a 20 teeth external gear. The planet gear 3 is a 40 teeth external gear. The ring gear 5 is a 100 teeth internal gear. The ring gear 5 is fixed and the gear 2 is rotating at 50 rpm CCW (CCW = counter-clockwise and CW = clockwise).
The arm 4 attached to the output shaft will rotate at
(A) 10 rpm CCW
(B) 10 rpm CW
(C) 12 rpm CW
(D) 12 rpm CCW