Remember that
The formula for the future value of an ordinary annuity is equal to:

where
FV is the future value
P is the periodic payment
r is the interest rate in decimal form
n is the number of times the interest is compounded per year
t is the number of years
In this problem we have
P=$500
r=3%=0.03
t=3 years
n=12
substitute in the formula

FV=$18,810.28