Hey guys, this is my first post, was just wondering if i could get your help. I'm studying for my repeats and you guys can save me.

If X = {1,2,3,4}, Y = {2,4,6} what is the cardinality of the following sets?

(i) A = {x|x mod 2 = 0 and 0 <=x<=20}

(ii) B = X * X * Y

(iii) C = {(x,y)|x ≠ y and x,y ∈ X}

Please explain your train of thought in solving this. I am trying hard to understand the right way to approach this question quickly, Thank you for your time guys...