(a)the total amountof principal plus simple interest due after 2 years if nointermediate payments are made :
P=$2000
R=4%
T=2×12=24
$$Simple\;Interest=P\left(1+\frac{r\times t}{100}\right)$$
$$=2000\left(1+\frac{4\times24}{100}\right)$$
=3920
(b)The total amount of principal plus compounded interest due after 2 years if no intermediate payments are made:
$$=P\left(1+\frac r{100}\right)^t$$
$$=2000\left(1+\frac4{100}\right)^{24}$$
=5126
(c)The nominal interest rate when the interest rate is compounded monthly:
=12×4
=48% per year compounded monthly
(d)The effective interest rate when the interest is compounded monthly:
$$=\left(1+\frac rn\right)^n-1$$
$$=\left(1+\frac{48}{100\times12}\right)^{12}-1$$
=0.6010
therefore effective interest rate =60.1%