Then show that  the number of relations containing (1, 2)
and (2, 3) which are reflexive and transitive but not symmetric is three Solution The smallest relation R1 containing (1, 2) and (2, 3) which is reflexive and
transitive but not symmetric is {(1, 1), (2, 2), (3, 3), (1, 2), (2, 3), (1, 3)} Now, if we add
the pair (2, 1) to R1 to get R2, then the relation R2 will be reflexive, transitive but not
symmetric Similarly, we can obtain R3 by adding (3, 2) to R1 to get the desired relation