Answer:
4 dozens
Step-by-step explanation:
Find Eleanor and Joanna's ratio of eggs to milk
Eleanor:
Dozen eggs : gallons of milk
9 : 3
3 : 1
Joanna:
Dozen eggs : gallons of milk
2 : 2
1 : 1
They gather one gallon of milk each which means Joanna has 1 dozen eggs and Eleanor has 3 dozens of eggs.
Total dozen of eggs = 3 + 1 = 4
Therefore, total dozen of eggs the family have per week is 4 dozens.