A motor produces 12 gcm of torque. Assuming no friction losses. Using the following gears (tooth numbers), identify 2 sets of gears (each set consisting of 2 gears) that will increase the torque to 48 gcm. If the motor spins at 312 rpm, what is the rpm of the shaft of the follower gear? Gear sizes (by number of teeth): 10, 15, 20, 30, 40, 60, 80, 100