Question

At what rate percent (simple interest) will a sum of money double itself in 16 years?

• A. $6\frac{1}{4}$%
• B. $5\frac{1}{4}$%
• C. $5\frac{3}{4}$%
• D. $6\frac{3}{4}$%

Answer 1

The correct option is A $6\frac{1}{4}$%

Here, interest is to become equal to the principal in 16 years.
Suppose principal $=x$

Then amount $=2x$
$\therefore$ Interest =$x$
$R=\frac{SI\times 100}{P\times T}=\frac{100\times 100}{100\times 16}=\frac{25}{4}=6\frac{1}{4}$%