Answer:
39 years
Step-by-step explanation:
Adapt the formula A = P(1 + r)^n, letting P represent the original population, r the growth rate as a decimal fraction, and n the number of years.
Solve this for n:
2 billion = (1.353 billion)(1 + 0.01)^n
After simplification, we have:
2
--------- = 1.01^n
1.353
Taking the log of both sides, we get:
log 2 - log 1.353 = n log 1.01, or
log 2 - log 1.353 0.1697
------------------------ = -------------- = 39 years (rounded off from 39.28)
log 1.01 0.0043
