S is a relation over the set R of all real numbers and its is given by (a, b) ϵ S ⬄ ab ≥ 0. Then, S is

Let A = {1, 2, 3}. Then, the number of equivalence relations containing (1, 2) is

The relation R = {(1, 1), (2, 2), (3, 3)} on the set {1, 2, 3} is

If the set Z of all integers, which of the following relation R is not an equivalence relation?

Let A = {1, 2, 3} and consider the relation R = {(1, 1), (2, 2), (3, 3), (1, 2), (2, 3), (1, 3)}. Then, R is