Answer: 27.071 years.
Explanation:
The given function :
is used to model the population of an organism in a specific region after t years.
To find : t , when P(t)=1000
Substitute P(t)=1000 in the given function , we get
Taking natural log on both sides , we get

Hence, The number of organisms will be 1000 after t= 27.071 years.