Pointing to a boy,Seema said,"He is the son of my grandfather's only child". How is the boy related to Seema?

$I. A, B, C, D, E$ and $F$ are six members of a family.
$II.$ One couple has parents and their children in the family.
$III. A$ is the son of $C$ and $E$ is the daughter of $A$.
$IV. D$ is the daughter of $F$ who is the mother of $E$.
What relationship do $D$ and $E$ bear to each other?

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 $X$ related to $Q$?

Read the following information carefully and answer the question given below. All the six members of a family $A, B, C, D, E,$ and $F$ are travelling together. $B$ is the son of $C$ but $C$ is not the mother of $B$. $A$ and $C$ are a married couple. $E$ is the brother of $C$. $D$ is the daughter of $A$. $F$ is the brother of $B$. How many children does $A$ have?

$A$ 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 many nephews does $F$ have?

$A$ 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 $P$. Who is the brother-in-law of $R$?