One sixth of his life was a happy childhood;

After living a twelfth of his life, a sparse beard grew on his cheeks;

He got married and spent a seventh of his life;

In another five years, he has a son and feels very happy;

But the son only lived half his father's age;

After his son died, he spent four years in extreme grief and died.

(1) The life of Diophantine;

(2) Diophantine's age as a father;

(3) The age of Diophantine's son when he died.