Question

Suppose the population of a country in 1985 was 145 million. In 1995 it was 190 million. Use the formula
`P = Ae^(kt)` to setup an expression to estimate the population of the country in 2005.

A.
`P = 145e^((0.027)(10))`
B.
`P = 145e^((0.027)(20))`
C.
`P = 190e^((0.027)(10))`
D.
`P = 190e^((0.027)(20))`

Answer 1

we have given an expression
`P=Ae^(kt)`

in 1985 the population was 145 million which mean t=0.

`P=145` when 1985 ,t=0 .

from 1985 to 2005 there 20 years passed.so t=20

so
`P=145e^(0.027*20)`.

here k =0.027 which is growth constant it means it increasing at 2.7 % per year .

so option B will be the answer.