Pointing to a person,a man said to a woman,"His mother is the only daughter of your father." How was the woman related to the person?

$A + B$ 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 $P = R + Q$ mean?

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 $B$?

$X - Z$ 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?

Pointing to a photograph,a woman says,"This man's son's sister is my mother-in-law." How is the woman's husband related to the man in the photograph?

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 $Q$ related to $Z$?