The compound interest on a sum Rs.$25,000$ after $3years$ at the rate of $12\%p.a$ is

$P=$Rs.25000

$T=3years$

$\Rightarrow n=3$

$R=12\%p.a$

$A=P{(1+\frac{R}{100})}^n$

$=25,000{(1+\frac{12}{100})}^3$

$=25,000\times \frac{112}{100}\times \frac{112}{100}\times \frac{112}{100}$

$=\frac{112\times 112\times 112}{4\times 10}$

$=\frac{28\times 112\times 112}{10}$

$=35123.20$

$C.I=A-P$

$=32123.20-25,000$

$=10123.20$