Question

on what sum will the compound interest at 15/2 % per annum for 3 years compounded annually be ₹ 3101.40

Answer 1

$\textbf{Given:}$

$\text{Amount=Rs.}3101.40$

$\text{Rate of interest, r=}7.5\%$

$\text{Number of years, n=3 years}$

$\textbf{To find:}$

$\text{Sum(principal)}$

$\textbf{Solution:}$

$\textbf{Compund interest formula:}$

$\textbf{Amount=}\bf\,P(1+\frac{r}{100})^n$

$\implies\,3101.40=P(1+\frac{7.5}{100})^3$

$\implies\,3101.40=P(\frac{107.5}{100})^3$

$\implies\,3101.40=P(\frac{1075}{1000})^3$

$\implies\,3101.40=P(\frac{43}{40})^3$

$\implies\,P=(\frac{40}{43})^3{\times}3101.40$

$\implies\,P=\dfrac{64000}{79507}{\times}3101.40$

$\implies\boxed{\bf\,P=Rs.2496.50}$