Question

Rekha deposited Rs 16000 in a foreign bank which pays interest at the rate of 20% per annum compounded quarterly, find the interest received by Rekha after one year.

Answer 1

$$\begin{gathered} \mathrm{Given}: \\ \mathrm{P}=\mathrm{Rs}16,000 \\ \mathrm{R}=20\%\mathrm{p}.\mathrm{a}. \\ \mathrm{n}=1\mathrm{year} \\ \mathrm{We}\mathrm{know}\mathrm{that}: \\ \mathrm{A}=\mathrm{P}{\left(1+\frac{\mathrm{R}}{100}\right)}^{\mathrm{n}} \\ \mathrm{When}\mathrm{compounded}\mathrm{quarterly},\mathrm{we}\mathrm{have}: \\ \mathrm{A}=\mathrm{P}{\left(1+\frac{\mathrm{R}}{400}\right)}^{4\mathrm{n}} \\ =\mathrm{Rs}16,000{\left(1+\frac{20}{400}\right)}^4 \\ =\mathrm{Rs}16,000{\left(1.05\right)}^4 \\ =\mathrm{Rs}19,448.10 \\ \mathrm{Also}, \\ \mathrm{CI}=\mathrm{A}-\mathrm{P} \\ =\mathrm{Rs}19,448.1-\mathrm{Rs}16,000 \\ =\mathrm{Rs}3,448.10 \\ \mathrm{Thus},\mathrm{the}\mathrm{interest}\mathrm{received}\mathrm{by}\mathrm{Rekha}\mathrm{after}\mathrm{one}\mathrm{year}\mathrm{is}\mathrm{Rs}3,448.10. \end{gathered}$$