Examples of Math Problems: how long will it take for the population of a certain country to quadruple if its annual growth rate is 2.5% round to the nearest year.

Wednesday, July 24, 2013

how long will it take for the population of a certain country to quadruple if its annual growth rate is 2.5% round to the nearest year.

Growth model:
%0D%0A4P%5B0%5D+=P%5B0%5D%281%2B0.025%29%5Et%0D%0A

%0D%0A4P%5B0%5D+=P%5B0%5D%281%2B0.025%29%5Et%0D%0A

which we simplify to get

%0D%0A4+=%281%2B0.025%29%5Et%0D%0A

%0D%0A4+=%281%2B0.025%29%5Et%0D%0A

solving for t ...
ln%284%29=t%2Aln%281.025%29%0D%0A

ln%284%29=t%2Aln%281.025%29%0D%0A

ln%284%29%2Fln%281.025%29=t%0D%0A

this is about 81 years

No comments:

Subscribe to: Post Comments (Atom)