Question

Let A be {1, 2, 3, 4}, U be set of all natural numbers, then U-A’(complement of A) is given by set.

(a) {1, 2, 3, 4, 5, 6, ….}

(b) {5, 6, 7, 8, 9, ……}

(c) {1, 2, 3, 4}

(d) All of the mentioned

This question was posed to me by my college professor while I was bunking the class.

This interesting question is from Set Operations in portion Basic Structures: Sets, Functions, Sequences, Sums and Matrices of Discrete Mathematics

Answer 1

The correct option is (c) {1, 2, 3, 4}

To explain I would say: U – A’ ≡ A.