With little info to go on, my guess is that the ages were 4 and 11, based on flimsy reasoning. 4³=64 (close to 67) and 11³=1331 (close to 1433). 67/64=1.05, 1433/1331=1.08 approx.
A more robust and logical solution is based on the fact that 1433+67=1500. If we consider the age range 3 to 18 as the age of children, then that’s a range of 15 years. If each year is represents by 100 units, then 67 is equivalent to 0.67 year (about 8 months) and 1433 is equivalent to 14.33 years (14 years 4 months). The lowest age is 3 years (0 units) so 0.67 years is 3 years 8 months and 14.33 years is 17 years 4 months (1433 units).
