In Relation puzzle type, mutual blood relations or other information of more than two persons are mentioned and information about any two is mentioned.
E is the son of A.
D is the son of B.
E is married to C.
C is B's daughter.
How is D related to E ?
C is B's daughter and D is B's son. So, D is the brother of C.
E is a male married to C. So, E is the husband of C,
whose brother is D. So, D is the brother-in-law of E.