Question

At what rate per cent per annum simple interest will a sum double itself in $10$ years?

• A. $8\%$
• B. $10\%$
• C. $12\%$
• D. $12\frac{1}{2}\%$

Answer 1

The correct option is B $10\%$

To double a sum in simple interest,

$A=P+SI$

Now, A=2P$

$2P=P+SI$

$P=SI$

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

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

Given, $T=10Yrs$

$\frac{R\times 10}{100}=1$

$R=\frac{10}{100}=10$

Ans is $R=10\%$

Oprion $\text{B}$ is correct