Question

7. The population of Flood River City is now 42,000. Experts predict the population will decrease 25% each

year for the next five years. What will be the population in five years?

Answer 1

Answer: The population after five years = 9967

Explanation:

The exponential equation for population decay :
`P=A (1-r)^t`, where A = initial population r= rate of decay , t= time

Given: A= 42000, r= 25%= 0.25, t= 5

then

`P=42000(1-0.25)^5\\\\=42000(0.75)^5\\\\=42000(0.2373046875)\\\\\approx9967`

Hence, The population after five years = 9967