Question

A town's population is currently 30,000. If the population doubles every 45 years, what will the population be 90 years from now?

A. 240,000 people
B. 150,000 people
C. 120,000 people
D. 60,000 people

Answer 1

C. 120,000 people

Explanation:

First thing I did was divide 90 by 45 which gave me 2 as my answer. So now I know that the population 90 years from now will be doubled twice (x4). So I did...

`30,000 * 4 = 120,000`

Answer 2

80,000 people

Explanation:

First, find out how many times the population will double. Divide the number of years by how long it takes for the population to double.

68÷34=2

The population will double 2 times.

Now figure out what the population will be after it doubles 2 times. Multiply the population by 2 a total of 2 times.

20,00022=80,000

That calculation could also be written with exponents:

20,00022=80,000

After 68 years, the population will be 80,000 people.