Blood Relations

If A is the father of B, but B is not his son, how is B related to A?

If John is the brother of Mary, and Mary is the mother of Peter, how is John related to Peter?

Pointing to a woman, Tom says, "She is the daughter of the only child of my grandmother." How is the woman related to Tom?

Pointing to a photograph, Sarah said, "He is the son of the only son of my grandfather." How is the man in the photograph related to Sarah?

If X is the brother of Y, Y is the sister of Z, and Z is the father of W, how is Y related to W?

If M's father's only daughter is N, and N is the mother of O, how is M related to O?

If P is the mother of Q, and R is the sister of P, how is Q related to R?

Introducing a woman, a man says, "She is the wife of my mother's only son." How is the woman related to the man's father?

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

If P is the son of Q, and R is Q's sister, S is R's mother, and T is S's husband, how is T related to P?