About 4,000 new species of marine animals were discovered in the last 2 years. What is the unit rate of discovery?
To find the unit rate of discovery, we need to divide the total number of new species discovered by the number of years.
Total number of new species discovered: 4,000
Number of years: 2
Unit rate of discovery = 4,000 / 2 = 2000
Therefore, the unit rate of discovery is 2000 new species per year.