$E$ 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 $E$?

$A$ is the son of $B$; $C$,$B$'s sister,has a son $D$ and a daughter $E$; $F$ is the maternal uncle of $D$. How many nephews does $F$ have?

If $A \times B$ means $B$ is father of $A$,$A + B$ means $A$ is wife of $B$,and $A \div B$ means $A$ is brother of $B$,then what is the relation of $J$ with $L$ in $J + H \div R \times L$?

Pointing to a gentleman,Deepak said,"His only brother is the father of my daughter's father." How is the gentleman related to Deepak?

$I. A, B, C, D, E$ and $F$ are six members of a family.
$II.$ One couple has parents and their children in the family.
$III. A$ is the son of $C$ and $E$ is the daughter of $A$.
$IV. D$ is the daughter of $F$ who is the mother of $E$.
What relationship do $D$ and $E$ bear to each other?

Pointing to a photograph,Vipul said,"She is the daughter of my grandfather's only son." How is Vipul related to the girl in the photograph?