First we need to find the amount after 20 years
The formula is
A=p (1+r/n)^nt
A future value?
P present value 200000
R interest rate 0.045
n compounded monthly 12
T time 20 years
A=200,000×(1+0.045÷12)^(12×20)
A=491,093.27
Now find the interest
I=A-p
I=491,093.27−200,000
I=291,093.27.....Answer
Hope it helps!