About 1.5 million species have been described…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
About million species have been described. Suppose that the true total is million species.
- What share of the species has been described, in per cent?
- How many species are still to be described, in millions?
- If the true total were million species, what share would have been described, in per cent?
Need a reminder? The key ideaShow
About 1.5 million species are described. Estimates of the total run from 7 million to 50 million. Animals are more than 70 per cent of the described species, plants are no more than 22 per cent, and insects are more than 70 per cent of the animals. The diversity is highest in the tropics and falls towards the poles.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Given. Described million. Total million, or million.
Step 1. (a) per cent.
Step 2. (b) million species.
Step 3. (c) per cent.
Answer: per cent; million species; per cent.
Check. A larger total leaves a smaller share known.
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