Question

A sum of money invested at 8% per annum amounts to Rs 12122 in 2 years. What will it amount to in 2 years 8 months at 9% per annum?

Answer 1

$\begin{array}{l}\text{Let the required sum be Rs.}x.\\ \\ \text{S}\text{.I.=}\frac{\text{P×R×T}}{\text{100}}=\frac{x\times 8\times 2}{100}=\frac{16x}{100}\\ \text{A}=\text{P}+\text{S}.\text{I.}\\ =x+\frac{16x}{100}=\frac{100x+16x}{100}=\frac{116x}{100}\\ \text{But the amount is Rs}\text{. 12122.}\\ =>\frac{116x}{100}=12122\\ =>x=\frac{12122\times 100}{116}=10450\\ \\ \mathrm{Now,}\text{S}\text{.I.=}\frac{\text{P×R×T}}{\text{100}}=\frac{1045\sout{0}\times {\sout{9}}^3\times \sout{3}{\sout{2}}^8}{10\sout{0}\times \sout{1}{\sout{2}}_{4_1}}=\text{Rs}.2508\\ \therefore \text{A=P+S}\text{.I.}\\ \text{= Rs}\text{. 10450 + Rs}\text{. 2508}\\ \text{= Rs}\text{. 12958}\end{array}$