Nice, you're getting into set theory! I am not the best at this stuff, but I'll try :D
For teh first one:
Whenever we see an apostrophe next to the set, it means to take the complement of that set. This means, it includes all the things that ARE NOT n that set. For this one, it says X', which means everything that is not in X. So it would be C :D
For teh second one:
(i) So you see that "U" symbol? That "U" stands for Union: Everything that is in A or B. This also includes everything in A and B, so basically just A + B. Here, it would be everything in the circles - 8, 14, 17, 16, 9 and 12.
(ii) This "n" symbol is kind of the opposite, but not really - it stands for an Intersection. This one is fairly obvious to understand - it is everything which is in the intersection of A and B :)
Here, it would be 14 and 17 :D
b) I'm not sure what that "/" symbol is on top of the A, but I'm assuming the question-makers tried to make an apostrophe (a complement). I trust that you can now solve this one on your own! :D