Question

At what rate percent per annum compound interest will Rs. $10000$ amount to Rs. $13310$ in three years?

• A. $5\%$
• B. $10\%$
• C. $12.5\%$
• D. $24\%$

Answer 1

The correct option is B $10\%$

Let the required rate be $x\%$ p.a.

Here,$A=Rs.13310,P=Rs.10000,t=3$ years.

Using formula:

$A=p{(1+\frac{R}{100})}^n$

$⟹13310=10000{(1+\frac{x}{100})}^3$

$13310=10000{\left[\frac{(100+x)}{100}\right]}^3$

$⟹\frac{13310}{10000}={\left[\frac{(100+x)}{100}\right]}^3$

$⟹{\left(\frac{11}{10}\right)}^3={\left[\frac{(100+x)}{100}\right]}^3$

$⟹\frac{11}{10}=\frac{(100+x)}{100}$

$⟹11\times 100=10\times (100+x)$

$⟹1100=1000+10x$

$⟹1100-1000=10x$

$⟹10x=100$

$x=10$

Hence ,the required rate $=10\%p.a$.