If one magnet is mounted on a shaft, and another one is brought close with alike pole what happens to the magnets

Like repels like; they will repel.

that would be because of both gravity and friction. so     c

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.