$A$ girl introduced a boy as the son of the daughter of the father of her uncle. The boy is the girl's:

$A + B$ means $A$ is the daughter of $B$. $A - B$ means $A$ is the husband of $B$. $A \times B$ means $A$ is the brother of $B$.
If $P + Q - R$,which of the following is true?

Pointing to a girl in the photograph,Amar said,"Her mother's brother is the only son of my mother's father." How is the girl's mother related to Amar?

$A + B$ means $A$ is the father of $B$; $A - B$ means $A$ is the wife of $B$; $A \times B$ means $A$ is the brother of $B$; $A \div B$ means $A$ is the daughter of $B$. If $P \times R - Q$,which of the following is true?

$A \div B$ means $A$ is the father of $B$,$A - B$ means $A$ is the wife of $B$,$A \times B$ means $A$ is the brother of $B$,$A + B$ means $A$ is the daughter of $B$.
If $P \div R + S + Q$,which of the following is true?

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 $D$?