Answer:
The answer to the question is
She must invest $251.85 each month to reach her goal
Step-by-step explanation:
Future value of an annuity is the amount a given stream of cash flows will be worth after a specified period. The future value represents the cumulative accumulation of payments made or borrowed and their respective interest made or interest charged.
The future value is given by

Where
FV = Future value =$30,000
PMT = Payment =
r = Interest rate for a given period = 6 % monthly
n = Number of periods of payments = 3 years or 36 months
Therefore we have
= PMT×119.12
Therefore PMT = 30000÷119.12 = $251.85
Therefore She would have to save $251.85 monthly to make up $30,000 in three years