Rohit deposited Rs 8000 with a finance company for 3 years at an interest of 15% per annum.

We know that amount $A$ at the end of n years at the rate of $R \%$ per annum is given by $A=P\left(1+\frac{R}{100}\right)^{n}$.

Given:

$\mathrm{P}=\mathrm{Rs} 8,000$

$\mathrm{R}=15 \%$ p. a

$\mathrm{n}=3$ years

Now,

$\mathrm{A}=8,000\left(1+\frac{15}{100}\right)^{3}$

$=8,000(1.15)^{3}$

$=\mathrm{Rs} 12,167$

And,

CI $=\mathrm{A}-\mathrm{P}$

$=\mathrm{Rs} 12,167-\mathrm{Rs} 8,000$

$=\mathrm{Rs} 4,167$