As far i understood I'll explain you.
Here is the solution.
Income of milne 3776+income of savage.
Income of drugg 2*income of grocer
Income of architect 2*income of druggist
Income of banker 2*income of architect
from the above information we can compare as
Income of drugg 2*income of grocer
so d>g
Income of architect 2*income of druggist
so a > d
hence a>d>g
Income of banker 2*income of architect
so b>a
hence b>a>d>g
Having these comparisons ready Carter is older than every one who earns more than Flynn but Flynn does not earn double the amount of carter
so again going back to question
Income of milne 3776+income of savage.
Income of drugg 2*income of grocer
Income of architect 2*income of druggist
Income of banker 2*income of architect
Flynn does not earn double the amount of carter
> flynn is Architect
and again Carter is older than every one who earns more than Flynn
refering those comparisions b>a>d>g
carter must be Banker
As Income of milne 3776+income of savage.
milne earns more than savage. refering those comparisions b>a>d>g
Milne is Druggist and savage is Grocer.
Finally
Milne - Druggist
Savage - Grocer
Carter - Banker
Flynn - Architect