From 1980 to 1990, the population of Country X increased by 100%, and then by 50% from 1990 to 2000. What was the overall increase in population from 1980 to 2000?

From 1980 to 1990, the population of Country X increased by 100%, and then by 50% from 1990 to 2000. What was the overall increase in population from 1980 to 2000?

• A. 150%
• B. 166 2/3%
• C. 175%
• D. 200%

Answer: (D)

To determine the overall increase in population from 1980 to 2000, we can break it down into two parts: the increase from 1980 to 1990 and the increase from 1990 to 2000. Let's assume the population in 1980 is represented by P. 1. From 1980 to 1990, the population increased by 100%. This means the population doubled. Therefore, by 1990, the population would be: \[ P + 100\% \text{ of } P = 2P \] 2. From 1990 to 2000, the population increased by 50%. This means that the population would grow by half of the 1990 population: \[ 2P + 50\% \text{ of } 2P = 2P + 1P = 3P \] Now, we can calculate the overall increase from the original population (P) in 1980 to the population (3P) in 2000: The overall increase in population is: \[ 3P - P = 2P \] To find the percentage increase from the

To determine the overall increase in population from 1980 to 2000, we can break it down into two parts: the increase from 1980 to 1990 and the increase from 1990 to 2000.

Let's assume the population in 1980 is represented by P.

1. From 1980 to 1990, the population increased by 100%. This means the population doubled. Therefore, by 1990, the population would be:

[

P + 100% \text{ of } P = 2P

]

2. From 1990 to 2000, the population increased by 50%. This means that the population would grow by half of the 1990 population:

[

2P + 50% \text{ of } 2P = 2P + 1P = 3P

]

Now, we can calculate the overall increase from the original population (P) in 1980 to the population (3P) in 2000:

The overall increase in population is:

[

3P - P = 2P

]

To find the percentage increase from the