See figure attached for question as well as my attempts.
I am not concerned with part (a), I have deduced that indeed X and Y are dependent.
I'm not sure if I have done part (b) correctly, and I am quite certain I have done part (c) incorrectly, but I couldn't think of what else to do.
Am I on the right track in parts (b) and (c)? What is incorrect, or how should I approach the problem?