Pebble lived 1/12 of his life as a small child and 1/6 more as a “youth”. Then he married Bloomie and lived happily 1/7 of his life plus 5 more years. Then they had a son, Nelius, whom, sadly, Pebble outlived by four years. Nelius lived to be 1/2 of Pebble’s final age. How old was Pebble when he died?
Pebble lived x years; his son lived x/2 years.
So x/12 + x/6 + x/7 + 5 + x/2 + 4 = x
This leads to 75x/84 + 9 = x, which leads to x = 84.