# How many bird species will there be left in the year 2020 if in 1990, a rural area had 1200 bird species and are becoming extinct at the rate of 1.5% per decade (10 years)?

Nov 3, 2014

Since the number of bird species becomes 98.5% of a previous decade, in 2020 (3 decades after 1990), the number of the bird species will be

$1200 {\left(0.985\right)}^{3} \approx 1147$ bird species.

I hope that this was helpful.