Question

Exponential Growth: The world population was 2010 about 7 billions; the yearly population growth is just below 2%. Assuming r=2% being stable:

How much time did elapse since the people were only 3.5 billion?

[Type the nummerical value rounded to full years ]

Answer 1

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
`e^(rt)`

here put all value

7 = 3.5
`e^(0.02t)`

take ln both side

ln (7/3.5) = ln
`e^(0.02t)`

0.02t = ln2

t = ln2 / 0.02

t = 24.66

so time is 24.66 years