Mary invests $10,000 at 4.5% interest a year, compounded quarterly.
(A)How much will she have after 20 years?
(B) If the interest were compound semi-monthly, how much more would Mary have after 20 years than compounded quarterly?
Equation
A=P[1+r/k]^kt
I got 24,472 after 20 years
But I dont know how to do the second part (B)