(b) A spur pinion has a diametral pith of 9 teeth/in, 45 teeth, and rotates at 800 rev/min. The pinion drives another spur gear at a speed of 400 rev/min. Find the number of teeth on the driven spur gear and the theoretical center-to-center distance. (9 marks) (c) In an exhaust fan, a set of gears is used to reduce the speed from a motor to the fan system (see Figure 1.1). The 20-tooth pinion gear on the motor has a diametral pitch of 5 and rotates at 1150 rpm clockwise. Determine the gear ratio of this set of gear, speed of the spindle (which has 60 teeth), and the pitch line velocity. (12 marks)