Don is a boy for 1/6 of his life.After 1/12 more,his beard grew.After another 1/7,he married.In the fifth year after his marriage,he was blessed with a son.the son lived half as many as his father.Don died on 4 years after his son.what was the age of Don when he died?



Don's son was born after 1/6+1/7+1/12 of his life +5 years. The son died 4 years before don and lived half as long.
Son was born in the year  (1/6+1/12+1/7)x+5
the son died in the year x-4
Subtracting the year of birth from the year of death- it's son's lifespan and half of fathers lifespan.
Solve this and you will get the answer