A mathematical model for population growth over short intervals is given by PequalsUpper P 0 e Superscript rt, where Upper P 0
is the population at time tequals0, r is the continuous compound rate of growth, t is the time in years, and P is the population at time t. How long will it take a country's population to triple if it continues to grow at its current continuous compound rate of 0.86% per year?