If $A+B$ means $A$ is the mother of $B$,$A \div B$ means $A$ is the brother of $B$,$A \times B$ means $A$ is the son of $B$,and $A-B$ means $A$ is the daughter of $B$,which of the following means $C$ is the niece of $D$?

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

$A$ 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 two married couples?

$C$ is $A's$ father's nephew. $D$ is $A's$ cousin but not the brother of $C$. How is $D$ related to $C$?

$A$ 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 $R$?

In a family,there are six members $A, B, C, D, E$ and $F$. $A$ and $B$ are a married couple,$A$ being the male member. $D$ is the only son of $C$,who is the brother of $A$. $E$ is the sister of $D$. $B$ is the daughter-in-law of $F$,whose husband has died.
How is $F$ related to $A$?