Question

A sum of ₹2000 amounts to ₹2662 in 3 years. The rate of compound interest per annum is________.

• A. 10

Answer 1

The correct option is A 10
Given that A = ₹ 2662 , P = ₹ 2000 and n = 3 years

Let the Rate of Interest be r

A=P ( 1+$\frac{r}{100}{)}^n$

$2662=2000(1+\frac{r}{100}{)}^3$

$\Rightarrow \frac{1331}{1000}=(1+\frac{r}{100}{)}^3$

$\Rightarrow (\frac{11}{10}{)}^3=(1+\frac{r}{100}{)}^3$
$\Rightarrow \left(\frac{11}{10}\right)=(1+\frac{r}{100})$
$\Rightarrow \left(\frac{11}{10}\right)$ = ( $\frac{100+r}{100})$
$\Rightarrow 110=100+r$
$\Rightarrow r=10\%$