A right-hand helical pinion is to drive a gear at a shaft angle of 90◦. The pinion has 6 teeth and a 75◦

helix angle and is to drive the gear at a velocity ratio of 6.5. The normal diametral pitch of the gear is 12 teeth/in. Calculate the helix angle and the number of teeth on the mating gear. Also determine the pitch radius of each gear.