You have now posted 3 different, but similar, problems with no sign of any attempt to solve them on your part. You can't learn mathematics that way! Are you able to list some numbers that are in sets X and Y.
(By the way, in mathematics, "x" and "y" may be quite different from "X" and "Y". Don't use small letters and Capital letters interchangabley.)
niraj, could you please show what approach you are going to take to solve it?
I'm assuming you don't have to proof any of those claims. Hence, you can start by doing some examples. I think you will realize this problem is much easier than you think!