The rear wheels of DeMarius’ car complete of a rotation for every full rotation of a front wheel. What is the radius, in feet, of a rear wheel on the car? Write your answer as a simplified fraction.

DeMarius’ original design for his car used rear wheels with a radius of 12 inches. What is the measure of the central angle of this rear wheel such that the arc length is equivalent to that of a full rotation of the rear wheel that is actually used on DeMarius’ car?