It would seem that part a) and part b) ARE unrelated.
You are given an angular velocity, measured in radians per second and asked to find the angle through which a wheel has rotated.
To find the angle through which a wheel rotates you must multiply the angular velocity by a time.
i.e.
However, you have not been given the time that you need. All you have been given is a normal speed, which is irrelevant for what you are trying to find.