If $(i)$ $M$ is brother of $N$; $(ii)$ $B$ is brother of $N$; and $(iii)$ $M$ is brother of $D$,then which of the following statements is definitely true?

$A$ 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 son of $B$; $C$,$B$'s sister,has a son $D$ and a daughter $E$; $F$ is the maternal uncle of $D$. How is $F$ related to $E$?

In a family,there are six members $A, B, C, D, E$ and $F$. $A$ and $B$ are a married couple,$A$ being the male member. $D$ is the only son of $C$,who is the brother of $A$. $E$ is the sister of $D$. $B$ is the daughter-in-law of $F$,whose husband has died.
How many male members are there in the family?

$A + B$ 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?

If $A + B$ means $A$ is the brother of $B$; $A \cdot B$ means $A$ is the father of $B$ and $A \times B$ means $A$ is the sister of $B$,which of the following means $M$ is the uncle of $P$?