List of top Applied Mechanics and Design Questions on Gears and gear trains

The Levai type-A train illustrated in the figure has gears with module m = 8 mm/tooth. Gears 2 and 3 have 19 and 24 teeth respectively. Gear 2 is fixed and internal gear 4 rotates at 20 rev/min counter-clockwise. The magnitude of angular velocity of the arm is _____rev/min. (rounded off to 2 decimal places)
The Levai type-A train illustrated in the figure has gears with module m = 8 mm/tooth

A power transmission mechanism consists of a belt drive and a gear train as shown in the figure. 

Diameters of pulleys of belt drive and number of teeth (T) on the gears 2 to 7 are indicated in the figure. The speed and direction of rotation of gear 7, respectively, are