. a gear ratio is a direct measure of the ratio of the rotational speeds of two interlocking gears. it is calculated as the ratio of the number of teeth in the driven gear to the number of teeth in the drive (smaller) gear. a mechanic wants to design the gears with a gear ratio of approximately 3.87248. if he assumes that wheels cannot have more than 50 teeth on them, how many teeth should there be on each gear?