Introducing a man,a woman said,"He is the only son of my mother's mother." How is the woman related to the man?

Rita told Mani,"The girl $I$ met yesterday at the beach was the youngest daughter of the brother-in-law of my friend's mother." How is the girl related to Rita's friend?

Pointing to an old man,Kailash said,"His son is my son's uncle." How is the old man related to Kailash?

If $X$ is the brother of the son of $Y$'s son,how is $X$ related to $Y$?

If $A + B$ means $A$ is the sister of $B$,$A - B$ means $A$ is the brother of $B$,and $A \times B$ means $A$ is the daughter of $B$,which of the following shows the relation that $E$ is the maternal uncle of $D$?

All the six members of a family $A, B, C, D, E$ and $F$ are travelling together. $B$ is the son of $C$ but $C$ is not the mother of $B$. $A$ and $C$ are a married couple. $E$ is the brother of $C$. $D$ is the daughter of $A$. $F$ is the brother of $B$. How many male members are there in the family?