At what rate (in percentage, rounded off to two decimal place) per year will a sum of money 5 times

Let the principal be P.

The amount becomes 5 times the principal after 15 years:

Amount = 5P

So Simple Interest:

SI = 5P - P = 4P

Using the simple interest formula:

$SI=\frac{P \times R \times T}{100}$

Substitute values:

$4P=\frac{P \times R \times 15}{100}$

Cancel $P$:

$4=\frac{15R}{100}$

$R=\frac{400}{15}$

$R=26.666\ldots$

Rounded to two decimal places:

$R=26.67%$

Final Answer: 26.67%