The compound interest on a certain sum for 3 years at 15% p.a., interest compound yearly, is ₹4167. What is the simple interest on the same sum in $$4\frac{4}{5}$$ years at the same rate ?

$$C.I=P\left(1+\frac{r}{100}\right)^n - P$$

$$4167=P\left(1+\frac{15}{100}\right)^3-P$$

$$4167=P\left(\frac{23}{20}\times\ \frac{23}{20}\times\ \frac{23}{20}\right)-P$$

$$4167=P\left(\frac{12167}{8000}-1\right)$$

$$4167=P\left(\frac{4167}{8000}\right)$$

P=8000

Now, P = 8000, T= $$\frac{24}{5}\ \ years$$, R= 15%

S.I = $$\frac{P\times T\times R\ }{100}$$

=$$\frac{8000\times24\times15\ }{100\times\ 5}=5760$$.