An ancient Greek was said to have lived 1/4 of his live as a boy, 1/5 as a youth, 1/3 as a man, and

An ancient Greek was said to have lived 1/4 of his live as a boy, 1/5 as a youth, 1/3 as a man, and spent the last 13 years as an old man. How old was he when he died?

Set up his life equation per time lived as a boy, youth, man, and old man
1/4 + 1/5 + 1/3 + x = 1.

Using our LCM Calculator, we see the LCM of 3,4,5 is 60. This is our common denominator.

So we have 15/60 + 12/60 + 20/60 + x/60 = 60/60

Combine like terms
x + 47/60 = 60/60

Subtract 47/60 from each side:
x/60 = 13/60

x = 13 out of the 60 possible years, so he was 60 when he died.