If A + B means A is the brother of B; A - B means A is the sister of B and A x B means A is the father of B. Which of the following means that C is the son of M?

Vinod introduces Vishal as the son of the only brother of his father's wife. How is Vinod related to Vishal? 

Pointing towards a woman, Amit said, "She is the sister of my wife's husband." How is the woman related to Amit?

Vimal is the son of Mikka, and Nina is the daughter of Milan. Milan is the sister of Mikka. Who is Milan to Vimal? 

M is the son of P. Q is the granddaughter of O who is the husband of P. How is M related to O? 

If P is the husband of Q and R is the mother of S and Q. How is R related to P?

Pointing to a girl in a photograph, Sunita said, "She is the mother of Renu, whose father is my son". How is she(Sunita) related to that girl?