Answer:
9 3/13 grams per month
or 360 grams per month
Explanation:
Assume that mittens gain weight at a constant rate.
Use the rate equation:
change in value / time = rate
In this case, the change in value is weight gain, so the equation is:
weight gain / time = Rate
substitue in the values:
120g / 13 mont
= 9 3/13 g/month
Unless you mean that the time is 1/3 of a month then the equation when values substituted in would be:
120g / 1/3 month
= 360 g/month