Question

In the year 1999, the world population reached up to:
A. 1 billion
B. 3 billion
C. 6 billion
D. 7 billion

Answer 1

Hint:
The world population has grown very rapidly due to the death rate has gone down. Due to this the growth of food supplies and the improvement of medical facilities. Also, unlike the death rate, the birth rate is still quite a high rate. The birth rate and the death rate are the two major factors to influence the population change.

Complete solution:
In the year 1950, the world population was estimated at around 2.6 billion people. It reached 5 billion in the year 1987 and 6 billion in the year 1999. In October 2011, the global population was estimated to reach 7 billion. In the year 1999, less than 30 years later, the population doubled to the level of 6 billion. The main reason for this growth was that with better food supplies and medicine, deaths were decreased. Whereas the number of births still remained fairly high.

Additional Information: The birth rate is the number of live births per one thousand people. The death rate is the number of deaths happening per one thousand people.

Hence, the correct answer is option C.

Note:
The world population is hence projected to reach 8.5 billion levels in the year 2030. And also it will be 9.7 billion in the year 2050. This projection is having some degree of uncertainty related to the surrounding. These are on the basis of the medium projection variant. It is having the assumption of a decline of fertility for countries where large families are still prevalent.