Mathematics for IGCSE & O level - Sets (Section 1 - No. 23)

If the set A = {1, 3, 5, 7} and B = {7, 9, 11}, what is A ∩ B?

{7}

{1, 3, 5, 7, 9, 11}

{ }

{1, 3, 5, 9, 11}

The intersection contains only the common elements, which is 7.