Question

Roma borrowed Rs 64000 from a bank for $1\frac{1}{2}$ years at the rate of 10% per annum. Compute the total compound interest payable by Roma after $1\frac{1}{2}$ years, if the interest is compounded half-yearly.

Answer 1

$$\begin{gathered} \mathrm{Given}: \\ \mathrm{P}=\mathrm{Rs}64,000 \\ \mathrm{R}=10\%\mathrm{p}.\mathrm{a}. \\ \mathrm{n}=1.5\mathrm{years} \\ \mathrm{Amount}\mathrm{after}\mathrm{n}\mathrm{years}: \\ \mathrm{A}=\mathrm{P}{\left(1+\frac{\mathrm{R}}{200}\right)}^{2\mathrm{n}} \\ =64,000{\left(1+\frac{10}{200}\right)}^3 \\ =64,000{\left(1.05\right)}^3 \\ =\mathrm{Rs}74,088 \\ \mathrm{Now}, \\ \mathrm{CI}=\mathrm{A}-\mathrm{P} \\ =\mathrm{Rs}74,088-\mathrm{Rs}64,000 \\ =\mathrm{Rs}10,088 \end{gathered}$$