Mark passed 1/6 of his life in childhood, 1/12 in youth, and 1/7 more as a bachelor. Five years after his marriage, there was born a son who died four years before his father, at half his father's (final) age. How old was Mark when he died?

PleaseÊshow us how to do this problem.

I drew a pcture, I almost always draw a picture. If Mark died at the age of A years then his "life-line" was

Thus