$A$ man said to a lady,"Your mother's husband's sister is my aunt." How is the lady related to the man?

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?

Pointing to an old man,Kailash said,"His son is my son's uncle." How is the old man related to Kailash?

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

$M$ is $N$'s brother. $S$ is $D$'s mother and $M$'s aunt. How is $D$ related to $M$?

$P + Q$ means $P$ is the brother of $Q$; $P - Q$ means $P$ is the mother of $Q$; and $P \times Q$ means $P$ is the sister of $Q$. Which of the following means $M$ is the maternal uncle of $R$?