Answer :
5.75 (weight now) - 3.2 (weight at birth) = 2.55 (how much weight she has gained)
2.55 (how much weight she has gained) / 0.17 (weight gained per week) = 15 weeks
The baby is 15 weeks old.
2.55 (how much weight she has gained) / 0.17 (weight gained per week) = 15 weeks
The baby is 15 weeks old.