Question

What is the Cartesian product of A = {1, 2} and B = {a, b}?

(a) {(1, a), (1, b), (2, a), (b, b)}

(b) {(1, 1), (2, 2), (a, a), (b, b)}

(c) {(1, a), (2, a), (1, b), (2, b)}

(d) {(1, 1), (a, a), (2, a), (1, b)}

I got this question in an internship interview.

Enquiry is from Sets in portion Basic Structures: Sets, Functions, Sequences, Sums and Matrices of Discrete Mathematics

Answer 1

Correct choice is (c) {(1, a), (2, a), (1, b), (2, b)}

The best I can explain: A subset R of the Cartesian product A x B is a relation from the set A to the set B.