Find amount when principal rs10800 rate …

Given,
Principal (P) = 10,800
Time = 3 years
Rate (R) = {tex}12 \frac{1}{2}{/tex} per Annum compounded Annually.
{tex}=\frac{25}{2} \%{/tex}
Amount (A) = {tex}P\left(1+\frac{R}{100}\right)^{n}{/tex}
{tex}=10,800\left(1+\frac{\frac{25}{2}}{100}\right)^{3}{/tex}
{tex}=10,800\left(1+\frac{25}{2 \times 100}\right)^{3}{/tex}
{tex}=10,800\left(1+\frac{1}{2 \times 4}\right)^{3}{/tex}
{tex}=10,800\left(1+\frac{1}{8}\right)^{3}{/tex}
{tex}=10,800\left(\frac{8+1}{8}\right)^{3}{/tex}
{tex}=10,800 \times\left(\frac{9}{8}\right)^{3}{/tex}
{tex}=10,800 \times \frac{9 \times 9 \times 9}{8 \times 8 \times 8}{/tex}
{tex}=5400 \times \frac{9 \times 9 \times 9}{4 \times 8 \times 8}{/tex}
{tex}=2700 \times \frac{9 \times 9 \times 9}{2 \times 8 \times 8}{/tex}
{tex}=2700 \times \frac{81 \times 9}{2 \times 64}{/tex}
{tex}=2700 \times \frac{729}{128}{/tex}
{tex}=\frac{1968300}{128}{/tex}
Rs 15,377.34
Now, 
Amount = Principal + Interest
15377.34 = 10800 + Interest
15377.34 - 10.800 + Interest
4577.34 = Interest
{tex}\therefore{/tex} Interest = Rs 4, 577.34