If U = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12} and A = {3, 4, 7, 8, 9}, what is A′?
Note
A′ means the complement of A: all elements in the universal set U that are not in A. The complement is found by comparing A with the universal set. Every element in U that is missing from A belongs to A′. The correct answer is {1, 2, 5, 6, 10, 11, 12}, which matches the calculation or reasoning shown.