Answer:
The baby gained 1 pound after 4 weeks
Step-by-step explanation:
If we know that the baby weighted 7 pounds at birth and 12 after 20 weeks then we can subtract 7 from 12 to get 5 so we know that the baby gained 5 poundeds in 20 weeks so to find 4 weeks we can divide 20 by 5 to get 4 week and 5 weeks by 5 to get that the baby gained 1 pound in 4 weeks.
