Dan Brown writes on pages 305-306 in his book, Inferno,
"Venice hosted a staggering number of tourists each year -- an estimated one-third of 1 percent of the world's population -- some twenty million visitors in the year 2000.   With the additional billion added to the earth's population since that year, the city was now groaning under the weight of three million more tourists per year."
Using the statistics from Dan Brown's book, what was the world's population in the year 2000?

Solution to the Problem:

The answer is: 6 billion people.

Let x = population in the year 2000.
Then 1/3 of 1% of x = 20,000,000
So, .01x / 3 = 20,000,000
.01x = 60,000,000
x = 6,000,000,000.

This answer is close to the actual population figure for the year 2000, which was 6,055,049,000.

The United States Census Bureau estimates that the world population exceeded 7 billion on March 12, 2012.
That is an increase of 1 billion in just 12 years.   Overpopulation was at the heart of Dan Brown's novel.


Correctly solved by:

1. James Alarie Flint, Michigan
2. Chad Fore Gate City, Virginia
3. Patricia Young John Paul II Catholic High,
Tallahassee, Florida
4. Ryan Rignanese John Paul II Catholic High,
Tallahassee, Florida
5. Heejung Ahn John Paul II Catholic High,
Tallahassee, Florida
6. James DiMarco John Paul II Catholic High,
Tallahassee, Florida
7. Adam T. Oakley ----------