Question

Let Universal set U is {1, 2, 3, 4, 5, 6, 7, 8}, (Complement of A) A’ is {2, 5, 6, 7}, A ∩ B is {1, 3, 4}  then the set B’ will surely have of which of the element?

(a) 8

(b) 7

(c) 1

(d) 3

This question was posed to me during an internship interview.

I'm obligated to ask this question of Algebraic Laws on Sets in division Basic Structures: Sets, Functions, Sequences, Sums and Matrices of Discrete Mathematics

Answer 1

The correct answer is (a) 8

To explain I would say: The set A is {1,3,4,8} and thus surely B does not have  8 in it. Since 8 does not belong to A ∩ B. For other element like 7 we can’t be sure.