I am a student at the university of Hasselt (Belgium) in management, and I had to follow a statistical course. It is for me very difficult since I simply don't have any background in mathematics and statistics.

I am struggling with an exercise that might be easy but I really don't know where to start and so what to do. I know how to answer question b) but I don't know what are the mean and variance of Y. And I just don't know how to do a), which , I suppose, will help me to do b)

So if some could help me, I would be grateful!