Answer:
Carly needs to deposit $252.78 every month during 3 years to pay for her first year of college.
Explanation:
First we have to know how much is the amount of money that Carly needs to complete the $12,000, this is:

She will have to save $9,100 in 3 years (this are 36 months), now we can calculate the amount of money that she have to save every month dividing the money by the number of months:

Carly needs to deposit $252.78 every month during 3 years to pay for her first year of college.