Consider the non-empty set consisting of children in a family and a relation R defined as aRb if a is brother of b. Then R is
(A) symmetric but not transitive (B) transitive but not symmetric
(C) neither symmetric nor transitive (D) both symmetric and transitive
(B) transitive but not symmetric
If, aRb means a is brother of b.
Then, it does not mean b is also a brother of a. Because, b can be a sister of a too.
Therefore, R is not symmetric.
If, aRb implies that a is the brother of b.
and bRc implies that b is the brother of c.
Therefore, a must be the brother of c.
Hence, R is transitive.