Question

The difference between C. I. and S. I. on Rs. $10,000$ for two years is Rs. $64$ at the same rate of interest per annum. Find the rate of interest.

• A. $6$
• B. $7$
• C. $8$
• D. $9$

Answer 1

The correct option is C $8$

$CI={(1+\frac{R}{100})}^T-P$

$SI=\frac{PRT}{100}$

Given $P=10000,T=2,CI-SI=64$

$10000[{(1+\frac{R}{100})}^2-1]-\frac{20000R}{100}=64$

$\Rightarrow {\left(\frac{R}{100}\right)}^2+\frac{2R}{100}-\frac{2R}{100}=\frac{64}{10000}$

$\Rightarrow {\left(\frac{R}{100}\right)}^2={\left(\frac{8}{100}\right)}^2$

$\Rightarrow R=8$

$\therefore$ Rate of Interest is $8$%