Question

Let the set A is {1, 2, 3}  and B is {2, 3, 4}. Then the set  A – B is?

(a) {1, -4}

(b) {1, 2, 3}

(c) {1}

(d) {2, 3}

The question was posed to me during an internship interview.

The origin of the question is Set Operations in portion Basic Structures: Sets, Functions, Sequences, Sums and Matrices of Discrete Mathematics

Answer 1

The correct choice is (c) {1}

Best explanation: In A – B the common elements get cancelled.