A unit rate is when the denominator is 1. If we speak by months, that means we find th amount earned in 1 month.
Since 33,000 is earned in a year, and a year has 12 months, the current rate is 33000/12.
If we simplify that, we would get 2750/1.
The unit rate in months is $2750/1 mo.
Hope this helps! Have a great day :)