Lakshmi and Meena were Rohan's wives. Shalini is Meena's step-daughter. How is Lakshmi related to Shalini?

$A + B$ means $A$ is the father 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 daughter of $B$. If $P - R + Q$,which of the following statements is true?

$R$ is the daughter of $Q$. $M$ is the sister of $B$,who is the son of $Q$. How is $M$ related to $R$?

$P$ is the brother of $Q$. $M$ is the sister of $Q$. $T$ is the brother of $P$. How is $Q$ related to $T$?

$A$ 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 many nephews does $F$ have?

Pointing to a photograph,a man tells his friend,'She is the daughter of the only son of my father's wife'. How is the girl in the photograph related to the man?