Introducing a man to her husband,a woman said,"His brother's father is the only son of my grandfather." How is the woman related to this man?

$A$ family consists of six members $P, Q, R, X, Y,$ and $Z$. $Q$ is the son of $R$ but $R$ is not the mother of $Q$. $P$ and $R$ are a married couple. $Y$ is the brother of $R$. $X$ is the daughter of $P$. $Z$ is the brother of $P$. Which is a pair of brothers?

$A$ is the father of $C$. But $C$ is not his son. $E$ is the daughter of $C$. $F$ is the spouse of $A$. $B$ is the brother of $C$. $D$ is the son of $B$. $G$ is the spouse of $B$. $H$ is the father of $G$. Who is the grandmother of $D$?

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 daughter of $B$; $A \times B$ means $A$ is the son of $B$; and $A - B$ means $A$ is the wife of $B$. If $Z \times T - S \times U + P$,what is $U$ to $Z$?

$A$ family consists of six members $P, Q, R, S, T$ and $U$. There are two married couples. $Q$ is a doctor and the father of $T$. $U$ is the grandfather of $R$ and is a contractor. $S$ is the grandmother of $T$ and is a housewife. There is one doctor,one contractor,one nurse,one housewife,and two students in the family.
Which of the following is definitely a group of male members?