The relation R in the set {1, 2, 3} given by R = {(1, 1), (2, 2), (3, 3), (1, 2), (2, 3)} is

Reflexive only

Let A be a set in which the relation R defined.

1.R is said to be a Reflexive Relation (a, a) ∈ R

2. R is said to be a symmetric relation, if (a, b) ∈ R (b, a) ∈ R

3. R is said to be a transitive relation, if (a, b) ∈ R , (b, c) ∈ R (a, c) ∈ R

Given set is A = {1, 2, 3}

R = {(1, 1), (2, 2), (3, 3), (1, 2), (2, 3), (1, 3)} 

1.R is said to be a Reflexive Relation (a, a) ∈ R i.e., (1, 1), (2, 2), (3, 3)

2. R is said to be a symmetric relation, if (a, b) ∈ R ⇒ (b, a) ∈ R

3. R is said to be a transitive relation, if (a, b) ∈ R , (b, c) ∈ R (a, c) ∈ R.

So, relation is only reflexive.