Lakshmi and Meena were Rohan's wives. Shalini is Meena's step-daughter. How is Lakshmi related to Shalini?

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

$X - Z$ means $X$ is the mother of $Z$; $X \times Z$ means $X$ is the father of $Z$; and $X + Z$ means $X$ is the daughter of $Z$. If $M - N \times T + Q$,then which of the following is not true?

$A$ and $B$ are brothers,$C$ and $D$ are sisters. $A$'s son is $D$'s brother. How is $B$ related to $C$?

Introducing a man,a woman said,"His wife is the only daughter of my father." How is that man related to the woman?

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 $F$. What is the profession of $A$?