Let's bust some exponents
So let's try using these rules where we ran into trouble before. Recall that we got as far as finding the log in our equation -- now we can bust right past it...
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What is the doubling time?
(10 million -> 70 million in 1 hour)
Hint | Explanation | |
Substitute in the known info | 70 million = 10 million * 2n | |
Divide both sides by initial population | 7 = 2n | |
Bust that exponent | log(7) = n * log(2) | |
This looks complicated, but really all you need is a calculator | 0.84 = n * 0.30 | |
Now some rearranging... | n = 0.84 / 0.30 = 2.8 | |
So there were 2.8 generations in 60 minutes, so.... | 60 / 2.8 = 21.4 minutes each!! |
Bottom line: logs plus a calculator are a biologist's best friend....
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