$A$ man pointing to a photograph says,"The lady in the photograph is my nephew's maternal grandmother." How is the lady in the photograph related to the man's sister who has no other sister?

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?

$(i)$ In a family of six persons $A, B, C, D, E$ and $F$,there are two married couples.
$(ii)$ $D$ is grandmother of $A$ and mother of $B$.
$(iii)$ $C$ is wife of $B$ and mother of $F$.
$(iv)$ $F$ is the granddaughter of $E$.
How many male members are there in the family?

$A$ 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 $P$.
How many children does $P$ have?

There are six persons $A, B, C, D, E$ and $F$. $C$ is the sister of $F$. $B$ is the brother of $E$'s husband. $D$ is the father of $A$ and grandfather of $F$. There are two fathers,three brothers and a mother in the group. How many male members are there in the group?

If $X$ is the brother of the son of $Y$'s son,how is $X$ related to $Y$?