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

There is a family of six persons $A, B, C, D, E$ and $F$. They are 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 $F$?

Pointing to the lady on the platform,Manju said,"She is the sister of the father of my mother's son." Who is the lady to Manju?

Pointing to a lady,a girl said,'She is the daughter-in-law of the grandmother of my father's only son'. How is the lady related to the girl?

If $A+B$ means $A$ is the mother of $B$,$A \div B$ means $A$ is the brother of $B$,$A \times B$ means $A$ is the son of $B$,and $A-B$ means $A$ is the daughter of $B$,which of the following means $C$ is the niece of $D$?

Pointing to a photograph of Hari,Vijay said,"The father of his sister is the husband of my wife's mother". How is Vijay related to Hari?