Question

Polar bears are listed as a threatened species. In 2005, there were about 25,000 polar bears in the world. If

the number of polar bears declines by 1000 each year, in what year will there only be 1000 polar bears?
a.2030
b.2029
c.2028
d.2027

Answer 1

After subtracting the final desired polar bear population from the initial 2005 population and dividing by the annual decline, the year when the population reaches 1000 is calculated to be 2029, making option b the correct answer.

Step-by-step explanation:

The student's question involves a mathematical calculation to determine the year in which the polar bear population will decrease to a specific number, assuming a consistent rate of decline.

To calculate the year when there will only be 1000 polar bears left, we start with the initial population in 2005, which was 25,000 bears. The population is said to decline by 1000 bears each year. To find out how many years it will take for the population to reach 1000 bears, we subtract the final desired population (1000 bears) from the initial population (25,000 bears) and then divide the result by the annual decline rate (1000 bears/year).

1. Initial population: 25,000 bears
2. Desired population: 1000 bears
3. Annual decline: 1000 bears/year
4. Number of years until 1000 bears are left: (25,000 bears - 1000 bears) ÷ 1000 bears/year = 24 years

Since the starting point is the year 2005, we add the 24 years to find out the specific year:

• 2005 + 24 years = 2029

The correct answer to the student's question is b. 2029.