Pointing to a photograph,Nikita said,'She is the only granddaughter of my grandmother's daughter'. How is the girl in the photograph related to Nikita?

$A$ is the father of $C$. But $C$ is not his son. $E$ is the daughter of $C$. $F$ is the spouse of $A$. $B$ is the brother of $C$. $D$ is the son of $B$. $G$ is the spouse of $B$. $H$ is the father of $G$. Who is the grandmother of $D$?

$A$ and $B$ are a married couple. $X$ and $Y$ are brothers. $X$ is the brother of $A$. How is $Y$ related to $B$?

Five persons namely $P, Q, X, Y,$ and $Z$ are sitting in a park. $P$ is the mother of $X$,who is the wife of $Z$. $Y$ is the brother of $P$,and $Q$ is the husband of $P$. How is $Y$ related to $Q$?

$A + B$ means $A$ is the son 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 mother of $B$; and $A = B$ means $A$ is the sister of $B$.
What does $P \times R \div Q$ mean?

$A$ family consists of six members $P, Q, R, S, T$ and $U$. There are two married couples. $Q$ is a doctor and the father of $T$. $U$ is the grandfather of $R$ and is a contractor. $S$ is the grandmother of $T$ and is a housewife. There is one doctor,one contractor,one nurse,one housewife,and two students in the family.
Which of the following is definitely a group of male members?