Pointing to a man on the stage,Rita said,"He is the brother of the daughter of the wife of my husband." How is the man on the stage related to Rita?

$M$ is $N$'s brother. $S$ is $D$'s mother and $M$'s aunt. How is $D$ related to $M$?

Arun said,"This girl is the wife of the grandson of my mother." Who is Arun to the girl?

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

$A + B$ 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?

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 $F$?