Problema Solution
How long will it take for the population of a certain country to double if its annual growth rate is 7.8%?
Answer provided by our tutors
P0 = the initial population
r = 0.078 or 7.8%
t = ?
P(t) = P0*e^(rt)
we need to find t suck that P(t) = 2P0
2P0 = P0*e^(rt)
P0*e^(rt) = 2P0 divide both sides by P0
e^(rt) = 2
rt = ln 2
t = (ln 2)/r
t = (ln 2)/0.078
t = 8.9 years
it will take 8.9 year until the population doubles.