If P is the mother of Q, R is the brother of Q, and S is the father of R, then how is S related to P?

1. R is Q's brother, so they share parents. 2. P is Q's mother and S is R's father. 3. So S is also Q's father. 4. Husband of Q's mother = S is P's husband. _Source: SSC Stenographer Study Material, Chapter on Blood Relations (jkchrome.com, Mistral OCR'd PDF), section on parental relations_