If Kamal says,"Ravi's mother is the only daughter of my mother," how is Kamal related to Ravi?

Pointing to a photograph,Arun said,'She is the mother of my brother's son's wife's daughter.' How is Arun related to the lady?

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

There are six children playing football namely $A, B, C, D, E$ and $F$. $A$ and $E$ are brothers. $F$ is the sister of $E$. $C$ is the only son of $A$'s uncle. $B$ and $D$ are the daughters of the brother of $C$'s father. How is $D$ related to $A$?

If $A + B$ means $A$ is the sister of $B$,$A - B$ means $A$ is the brother of $B$,and $A \times B$ means $A$ is the daughter of $B$,which of the following shows the relation that $E$ is the maternal uncle of $D$?

$A$ 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 is definitely a group of male members?