Question

A butterfly population is decreasing at a rate of 0.82% per year. There are currently about 100,000 butterflies in the population. How many butterflies will there be in the population in 250 years?

Answer 1

12,765

Explanation:

The exponential formula for the population can be written as ...

population = (initial population)(1 -decay rate)^t

where t is in years, and the decay rate is the loss per year.

The given numbers make this ...

population = 100,000(0.9918^t)

In 250 years, the population will be about ...

population = 100,000(0.9918^250) ≈ 12,765.15

There will be about 12,765 butterflies in 250 years.