If a country's population growth rate is 5 percent what is the country's doubling time

We will use this formula:

Time = log (ending amount / beginning amount) : log (1 + rate)

For the purpose of this problem we'll say the population grows from 100 to 200.

Time = log (200 / 100) / log (1.05)

Time = log (2) / log (1.05)

Time =.30102999566 / 0.02118929907

Time = 14.207 years