Deepak is the brother of Ravi. Rekha is the sister of Atul. Ravi is the son of Rekha. How is Deepak related to Rekha?

In a family,there are six members $A, B, C, D, E$ and $F$. $A$ and $B$ are a married couple,$A$ being the male member. $D$ is the only son of $C$,who is the brother of $A$. $E$ is the sister of $D$. $B$ is the daughter-in-law of $F$,whose husband has died.
How is $F$ related to $C$?

In a family,there are six members $A, B, C, D, E$ and $F$. $A$ and $B$ are a married couple,$A$ being the male member. $D$ is the only son of $C$,who is the brother of $A$. $E$ is the sister of $D$. $B$ is the daughter-in-law of $F$,whose husband has died.
How many male members are there in the family?

Pointing to a lady,a girl said,"She is the daughter-in-law of the grandmother of my father's only son." How is the lady related to the girl?

Pointing to a photograph,a lady tells Pramod,"$I$ am the only daughter of this lady and her son is your maternal uncle." How is the speaker related to Pramod's father?

In a family,there are six members $A, B, C, D, E$ and $F$. $A$ and $B$ are a married couple,$A$ being the male member. $D$ is the only son of $C$,who is the brother of $A$. $E$ is the sister of $D$. $B$ is the daughter-in-law of $F$,whose husband has died.
Who is $C$ to $B$?