UPSC NDA II 2010 Mathematics Paper

Let U={1,2,3,...,20}. Let A,B,C be the subsets of U. Let A be the set of all numbers which are perfect squares, B be the set of all numbers which are multiples of 5 and C be the set of all numbers which are divisible by 2 and 3 .
Consider the following statements:
1. A,B,C are mutually exclusive.
2. A,B,C are mutually exhaustive.
3. The number of elements in the complement set of A∪B is 12 .
Which of the statements given above are correct?