Pointing to a photograph of a boy Raza said, "He is the son of the only son of my mother." How is Suresh related to that boy?

Pointing to a photograph of a boy Raza said, "He is the son of the only son of my mother." How is Suresh related to that boy?

Explanation

The boy in the photograph is the only son of the son of Raza's mother i.e., the son of Raza.

Hence, Raza is the father of boy.