10ticks Daily Puzzle

The Ravages of Time
This tomb holds Diophantus. Ah, what a marvel! and the tomb tells scientifically the measure of his life. God vouchsafed that he should be a boy for a sixth of his life; when twelfth was added, his cheeks acquired a beard; He kindled for him the light of marriage after a seventh and in the fifth year after his marriage he granted him a son. alas! Late-begotten and miserable child, when he reached the measure of half his fathers, the chill grave took him. After consoling his grief by the science of numbers for four years, he reached the end of his life. How long did Diophantus live?

The Ravages of Time

This tomb holds Diophantus. Ah, what a marvel! and the tomb tells scientifically the measure of his life. God vouchsafed that he should be a boy for a sixth of his life; when twelfth was added, his cheeks acquired a beard; He kindled for him the light of marriage after a seventh and in the fifth year after his marriage he granted him a son. alas! Late-begotten and miserable child, when he reached the measure of half his fathers, the chill grave took him. After consoling his grief by the science of numbers for four years, he reached the end of his life.
How long did Diophantus live?

Solution
84 years