Question

Today, the population of Canyon Falls is 22{,}50022,50022, comma, 500 and the population of Swift Creek is 15{,}20015,20015, comma, 200. The population of Canyon Falls is decreasing at the rate of 740740740 people each year while the population of Swift Creek is increasing at the rate of 1{,}5001,5001, comma, 500 people each year. Assuming these rates continue into the future, in how many years from today will the population of Swift Creek equal twice the population of Canyon Falls

Answer 1

10 years

Explanation:

Given :

Population of Canyon falls = 22500

Rate of decrease = 740 per year

Population after x years :

f(x) = 22500 - 740x ; x = number of years

Population of Swift Creek = 15200

Rate of Increase = 1500 per year

Population after x years :

f(x) = 15200 + 1500x ; x = number of years

Number of years when, population of swift creek will be twice that of Canyon falls

15200 + 1500x = 2(22500 - 740x)

15200 + 1500x = 45000 - 1480x

15200 - 45000 = - 1480x - 1500x

-29800 = - 2980x

x = 29800 / 2980

x = 10

After 10 years