Question 550212
If the population of a city doubles every 20 years, how long does it take to triple? (state this is logarithmic form and find solution)
:
An exponential formula
Ao*2^(t/20) = A
where 
Ao = initial amt
A = resulting amt in t time
If Ao = 1, then A = 3
2^(t/20) = 3
using nat logs we have
{{{t/20}}}*ln(2) = ln(3)
{{{t/20}}} = {{{ln(3)/ln(2)}}}
t = {{{ln(3)/ln(2)}}} * 20
t = 31.7 yrs
:
:
Check this on a calc, enter: 2^(31.7/20) results: 3.000