Question

In what time will $Rs.1000$ amount to $Rs.1331$ at $10\%$ per annum if interest is compounded anually?

• A. $4$ years
• B. $3$ years
• C. $2$ years
• D. $1$ years

Answer 1

The correct option is B $3$ years

Given:

$A=Rs.1331$

$P=Rs.1000$

$r=10\%$

We shall apply the formula for compound interest,

$A=P{\left(1+\frac{r}{100}\right)}^t$

$\Rightarrow 1331=1000{\left(1+\frac{10}{100}\right)}^t$

$\Rightarrow \frac{1331}{1000}=\left(\frac{11}{10}\right)$

$\Rightarrow {\left(\frac{11}{10}\right)}^t={\left(\frac{11}{10}\right)}^3$

$\Rightarrow t=3$ years

Hence, option $B$ is correct.