Consider the non-empty set consisting of children in a family and a relation R defined as aRb … nor transitive (d) both symmetric…
(b) aRb ⇒ a is brother of b.
This does not mean b is also a brother of a as b can be a sister of a.
Hence, R is not symmetric.
aRb ⇒ a is brother of b.
and bRc ⇒ b is a brother of c.
So, a is brother of c. Hence, R is transitive.