Pointing to the lady in the photograph,Mrinalini said,"Her son's father is the only son-in-law of my mother". How is Mrinalini related to the lady?

Pointing to a lady,a girl said,"She is the daughter-in-law of the grandmother of my father's only son." How is the lady related to the girl?

$A$ 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. Who is the husband of $P$?

$Q$ is the brother of $R$; $P$ is the sister of $Q$; $T$ is the brother of $S$; $S$ is the daughter of $R$. Who are the cousins of $Q$?

Pointing to a person,a man said to a woman,"His mother is the only daughter of your father." How was the woman related to the person?

Deepika tells Shraddha,"Your mother's father's son is the husband of my sister." How is Deepika related to Shraddha?