VITEEE 2011 Paper

Since, (1,4), (2,6) and (3,6) are the elements of A x B, therefore 1,2,3 are the elements of A and 4,6 are the elements of B.
Also, A x B has 6 elements ∴ A = {1,2,3} and B= {4,6}
∴ B x A= {(4,1), (4,2), (4,3), (6,1), (6,2), (6,3)}