Pointing to a photograph,Arun said,'She is the mother of my brother's son's wife's daughter.' How is Arun related to the lady?

There is a family of six persons $A, B, C, D, E,$ and $F$. They are a lawyer,doctor,teacher,salesman,engineer,and accountant. There are two married couples in the family. $D$,the salesman,is married to the lady teacher. The doctor is married to the lawyer. $F$,the accountant,is the son of $B$ and brother of $E$. $C$,the lawyer,is the daughter-in-law of $A$. $E$ is the unmarried engineer. $A$ is the grandmother of $F$. How is $D$ related to $F$?

$A$ man said to a lady,"Your mother's husband's sister is my aunt." How is the lady related to the man?

$A \div B$ 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 $P - R + Q$,which of the following statements is true?

Pointing towards a person in a photograph,Anjali said,"He is the only son of the father of my sister's brother." How is that person related to Anjali?

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