Question

A certain lake currently has an average trout population of 30,000. The population naturally oscillates above and below average by 3,000 every year. This year, the lake was opened to fishermen. If fishermen catch 4,000 fish every year, how long will it take for the lake to have no more trout?

Answer 1

it will be between 4 and 30 years

Explanation:

if the total average population is 30000

And the population is added by +-3000 every year,

And the fishermen catch 4000 every year

Assuming it reduces by 3000 every year,

we will have 7000 reduction every year

let n be the number of years

30000 -7000n = 0

30000/7000 = n

4.28 = 4years

Assuming it increases by 3000 every year,

we will have 1000 reduction every year

30000 - 1000n = 0

n = 30000/1000 = 30years