Question

The population of a certain animal species you are studying decreases at a rate of 3.5% per year. You have counted 80 of the animals in the habitat you are studying. How many animals will be there after 6 years? Round to the nearest whole #

Answer 1

65

Explanation:

Next year, there will be 3.5% fewer, so 100% - 3.5% = 0.965 times the number present this year. This same multiplication is repeated each year.

After 6 years, the number present will be 0.965^6 times the number this year, or ...

80 × 0.965^6 ≈ 80 × 0.80754 ≈ 64.60

There will be about 65 animals after 6 years.