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 $C$ related to $F$?

$A + B$ means $A$ is the daughter of $B$; $A \times B$ means $A$ is the son of $B$; and $A - B$ means $A$ is the wife of $B$.
If $P \times Q - S$,which of the following is true?

Deepak is the brother of Ravi. Rekha is the sister of Atul. Ravi is the son of Rekha. How is Deepak related to Rekha?

In a village of Bastar district in Madhya Pradesh,only two types of people live who belong to a tribal class. The first type is known as class $A$,while the other is known as class $B$. In that village,there is no other type of person except these two. The activities of both types of people are governed by perfectly patterned norms of social behaviour. Each person of the tribe has to obey the norms. They are rigid about this.
As far as marriage is concerned,the following norms are to be followed:
$(A)$ The people of class $A$ cannot marry any other member of their own class,though they can marry members of class $B$.
$(B)$ After being married,each male member ceases to be a member of that class in which he was born but automatically,he becomes the member of the other class to which his wife belongs.
$(C)$ As far as females are concerned,they remain the members of their own class after being married.
$(D)$ On his birth,the child automatically becomes the member of his mother's class.
$(E)$ When any male member becomes a widower or divorcee,then he again belongs to the group in which he was born.
$(F)$ Nobody can marry more than one person according to social laws.
Which of the following marriages is not permissible according to the social laws?

$A$ woman introduces a man as the son of the brother of her mother. How is the man related to the woman?

Pointing to a man in a photograph,Asha said,"His mother's only daughter is my mother." How is Asha related to that man?