Question

From 2003 onward, the number of daily visitors to a website increased by 200% every two years. So, for example, the number of visitors in 2011 was 200% more than the number of visitors in 2009.
In what year was the number of daily visitors $800\%$ more than the number of daily visitors in 2003?

Answer 1

It takes 4 years for number of daily visitors to be 800% more than the number of daily visitors in 2003

Solution:

Let the number of visitors in 2003 be 100

From 2003 onward, the number of daily visitors to a website increased by 200% every two years

Therefore, Number of visitors in 2005 is given as:

Visitors in 2005 = 100 + 200 % of 100

$Visitors\ in\ 2005 = 100 + \frac{200}{100} \times 100$

Visitors in 2005 is 300

Similarly, in 2007, the number of visitors is given as:

Visitors in 2007 = 300 + 200 % of 300

Visitors in 2007 = 300 + 600

Visitors in 2007 = 900

Now find the percentgae increase from 2003 to 2007

$\text { Percentage increase }=\frac{\text {visitors in } 2007-\text {visitors in } 2003}{\text {visitors in } 2003} \times 100$

$\text{percentgae increase} = \frac{900 - 100}{100} \times 100\\\\\text{percentgae increase} = 800$

Thus it is a 800 % increase

Number of years = 2007 - 2003 = 4 years

Thus it takes 4 years for number of daily visitors to be 800% more than the number of daily visitors in 2003