Pointing to a photograph,a person tells his friend,"She is the granddaughter of the elder brother of my father." How is the girl in the photograph related to the person?

$P$ is the brother of $Q$ and $R$. $S$ is $R$'s mother. $T$ is $P$'s father. Which of the following statements cannot be definitely true?

$P$ is the brother of $D$. $X$ is the sister of $P$. $A$ is the brother of $F$. $F$ is the daughter of $D$. $M$ is the father of $X$. Who is the uncle of $A$?

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 $J + H \div R \times L$?

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

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 children does $A$ have?