Answer:
Julia is 48. Her youngest child is 12 and her oldest is 16.
Explanation:
I guessed the youngest child's age (12) then I added 4 that equaled 16. Then I multiplied 12 by 4 which is 48. 48 plus 12 plus 16 equals 76. As for the 5d process I have no idea what that is your on your own for show work.