Answer:
time is 24.66 years
Explanation:
Given data
population A = 7 billion
rate = 2% = 0.02
population P = 3.5 billion
to find out
time
solution
we will apply here formula that is
A = P

here put all value
7 = 3.5

take ln both side
ln (7/3.5) = ln

0.02t = ln2
t = ln2 / 0.02
t = 24.66
so time is 24.66 years