In Relation puzzle type, mutual blood relations or other information of more than two persons are mentioned and information about any two is mentioned.
Deepak is brother of Ravi. Rekha is sister of Atul. Ravi is son of Rekha. How is Deepak related to Rekha ?
Deepak is the son of Ravi, who is the son of Rekha.
Thus, Deepak is the son of Rekha.