Question

Mark (✓) against the correct answer:
If the compound interest on a certain sum for 2 years at 10% per annum is Rs 1050, the sum is
(a) Rs 3000
(b) Rs 4000
(c) Rs 5000
(d) Rs 6000

Answer 1

(c) Rs. 5000

$$\begin{gathered} \mathrm{Here},A=\mathit{}P\times {\left(1+\frac{R}{100}\right)}^n \\ =P\times {\left(1+\frac{10}{100}\right)}^2 \\ =P\times {\left(\frac{110}{100}\right)}^2 \\ =\mathit{}P\times \left(\frac{11}{10}\right)\times \left(\frac{11}{10}\right) \\ Now,CI=A-P \\ \Rightarrow \mathrm{Rs}.1050=\frac{121p}{100}-P\mathit{} \\ =\frac{121P-100P}{100} \\ =\frac{21P}{100} \\ \therefore P=\mathrm{Rs}\frac{1050\times 100}{21}=\mathrm{Rs}5000 \end{gathered}$$