The difference in simple interest and compound interest on a certain sum of money

Given:

$\mathrm{CI}-\mathrm{SI}=46$

$\mathrm{P}\left[\left(1+\frac{\mathrm{R}}{100}\right)^{\mathrm{n}}-1\right]-\frac{\mathrm{PRT}}{100}=46$

$\mathrm{P}\left[\left(1+\frac{20}{300}\right)^{3}-1\right]-\frac{\mathrm{P} \times 20 \times 3}{3 \times 100}=46$

$\frac{4,096}{3,375} \mathrm{P}-\frac{\mathrm{P}}{5}-\mathrm{P}=46$

$\frac{(4,096-3,375-675) \mathrm{P}}{3,375}=46$

$\mathrm{P}=46 \times \frac{3,375}{46}$

$=3,375$

Thus, the required sum is Rs 3,375 .