Question

Tick (✓) the correct answer:
A sum of Rs 25000 was given as loan on compound interest for 3 years compounded annually at 5% per annum during the first year, 6% per annum during the second year and 8% per annum during the third year. The compound interest is
(a) Rs 5035
(b) Rs 5051
(c) Rs 5072
(d) Rs 5150

Answer 1

(b) Rs. 5051

$$\begin{gathered} \mathrm{Here},A=\mathrm{Rs}.P\mathit{}\times \left(1+\frac{p}{100}\right)\times \left(1+\frac{q}{100}\right)\times \left(1+\frac{r}{100}\right) \\ =\mathrm{Rs}.25000\times \left(1+\frac{5}{100}\right)\times \left(1+\frac{6}{100}\right)\times \left(1+\frac{8}{100}\right) \\ =\mathrm{Rs}.25000\times \left(\frac{105}{100}\right)\times \left(\frac{106}{100}\right)\times \left(\frac{108}{100}\right) \\ =\mathrm{Rs}.25000\times \left(\frac{21}{20}\right)\times \left(\frac{53}{50}\right)\times \left(\frac{27}{25}\right) \\ =\mathrm{Rs}.\left(21\times 53\times 27\right) \\ =\mathrm{Rs}.30051 \\ \therefore \mathrm{Compound}\mathrm{interest}=\mathrm{amount}-\mathrm{principal}=\mathrm{Rs}.(30051-25000)=\mathrm{Rs}.5051 \end{gathered}$$