For the set A = {1,2,3}, define the relation R on the set A as R = { (1,1), (2,2), (3,3) (1,3) }, the R is
Reflexive and symmetric
reflexive and transitive
symmetric and transitive
equivalence relation
(1, 3) ϵ R buy (3, 1) ∉ R ⇒ not symmetric
On the set Z of integers define a relation R by a R b if |a−b|≤3.Then R is