Question:

The sum that amounts to Rs 4913 in 3 years at $6 \frac{1}{4} \%$ per annum compounded annually, is

(a) Rs 3096

(b) Rs 4076

(c) Rs 4085

(d) Rs 4096

Solution:

(d) Rs 4096

We have Rs $4913=\left\{P \times\left(1+\frac{25}{100 \times 4}\right)^{3}\right\}$

$\Rightarrow \mathrm{Rs} 4913=\left\{P \times\left(\frac{16+1}{16}\right)^{3}\right\}$

$\Rightarrow \mathrm{Rs} 4913=\left\{P \times\left(\frac{17}{16}\right) \times\left(\frac{17}{16}\right) \times\left(\frac{17}{16}\right)\right\}$

$\Rightarrow \mathrm{Rs} 4913=\frac{4913 P}{4096}$

$\Rightarrow P=\mathrm{Rs} \frac{4913 \times 4096}{4913}=\mathrm{Rs} 4096$