Question

The S.I on a sum of money is $\frac{1}{9}th$ of the principal and the number of years is equal to the rate percent p.a. Find the rate $\%$.

Answer 1

Let the principal be $p$

Rate of intersect be $R$%

According to the question ,TIme$=R$

Simple interest $=\frac{p}{9}$

We know that,

$S.I=\frac{P\times R\times T}{100}$

$\Rightarrow \frac{P}{9}=\frac{\left(P\times R\times R\right)}{100}$

$\Rightarrow \frac{P}{9}=\frac{\left(P\times R^2\right)}{100}$

$\Rightarrow \frac{1}{9}=\frac{R^2}{100}$

$\Rightarrow R^2=\frac{100}{9}$

$\Rightarrow R=\frac{10}{3}$

Therefore,

rate of interest is $R=\frac{10}{3}$%