$E$ is the son of $A$. $D$ is the son of $B$. $E$ is married to $C$. $C$ is $B$'s daughter. How is $D$ related to $E$?

$A$ 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 female members are there in the family?

$A \div B$ means $A$ is the father of $B$,$A - B$ means $A$ is the wife of $B$,$A \times B$ means $A$ is the brother of $B$,$A + B$ means $A$ is the daughter of $B$.
If $P \div R + Q$,which of the following is true?

Introducing a man,a woman said,"He is the only son of my mother's mother." How is the woman related to the man?

$R$ is the daughter of $Q$. $M$ is the sister of $B$,who is the son of $Q$. How is $M$ related to $R$?

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 $B$. Who is the mother of $B$?