Question

A sum of money on compound interest amounts to Rs. $9,680$ in $2$ years and to Rs. $10,648$ in $3$ years. What is the rate of interest per annum?

• A. $5\%$
• B. $10\%$
• C. $15\%$
• D. $20\%$

Answer 1

Answer: (B)

$10\%$

Given that Rs. $9,680$ becomes Rs. $10,648$ in one year
therefore, $\text{Interest}=$ Rs. $10648-$ Rs. $9,680=$ Rs, $968$
$\Rightarrow \text{Rate}=\frac{\text{Interest}\times 100}{P\times t}$
$=\frac{968\times 100}{9680\times 1}=10\%$

Thus the rate of interest per annum is $10\%$.