(a) The number of times the last passenger who boarded the ride makes a complete loop on the Ferris wheel depends on the speed at which the Ferris wheel is rotating. Without knowing the speed, it's not possible to determine the exact number of loops.
As for the position of the passenger when the ride ends, again, it would depend on the starting position of the passenger and the speed at which the Ferris wheel is rotating. Without more information, it's not possible to determine the exact position.