$(i)$ In a family of six persons $A, B, C, D, E$ and $F$,there are two married couples.
$(ii)$ $D$ is the grandmother of $A$ and mother of $B$.
$(iii)$ $C$ is the wife of $B$ and mother of $F$.
$(iv)$ $F$ is the granddaughter of $E$.
Who among the following is one of the couples?

Pointing to a gentleman,Deepak said,"His only brother is the father of my daughter's father." How is the gentleman related to Deepak?

$A$ 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 are the two married couples?

Pointing to a woman,Nirmal said,"She is the daughter of my wife's grandfather's only child". How is the woman related to Nirmal?

$A$ 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?

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?