Rahul's mother is the only daughter of Monika's father. How is Monika's husband related to Rahul?

$M$ 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 $R$?

$X$ told $Y$,"Though $I$ am the son of your father,you are not my brother". How is $X$ related to $Y$?

$A$ 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 is $F$ related to $E$?

$A + B$ means $A$ is the son 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 mother of $B$; and $A = B$ means $A$ is the sister of $B$. What does $P + R - Q$ mean?