SOLUTION: please help me solve this: If he population of a city doubles every 20 years, how long does it take to triple? (state this is logarithmic form and find solution) please, i re

Question 550196: please help me solve this:
If he population of a city doubles every 20 years, how long does it take to triple? (state this is logarithmic form and find solution)
please, i really need your help!
Thanks in advance
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
If he population of a city doubles every 20 years, how long does it take to triple? (state this is logarithmic form and find solution)
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FP = PP*2^t (FP = future Pop, PP = present Pop, t in 20 year periods)
For FP = 3PP:
2^t = 3
t*log(2) = log(3)
t = log(3)/log(2)
# of years = 20t = 20log(3)/log(2)
years =~ 31.699
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You can use logs or ln, doesn't matter.

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