Question

The simple interest on a sum of money is $\frac{9}{25}$% of the principal and the rate percent is equal to number of years. The rate percent is

• A. 3%
• B. 4%
• C. 5%
• D. 6%

Answer 1

The correct option is D 6%

We know that, $SimpleInterest=\frac{Principal\times Time\times Rate}{100}$
According to the question,
Simple Interest=$\frac{9}{25}P$
R=T(Given rate percant is equal to number of years)
$\frac{9}{25}Principal=\frac{Principal\times Rate\times Rate}{100}$
$\frac{9}{25}=\frac{{Rate}^2}{100}$
$\frac{9}{25}=\frac{{Rate}^2}{100}$
$\frac{9}{25}={\left(\frac{Rate}{10}\right)}^2$
$\Rightarrow {\left(\frac{Rate}{10}\right)}^2=\frac{9}{25}$
$\Rightarrow \frac{Rate}{10}=\frac{3}{5}$
$Rate=\frac{3}{5}\times 10=6$%