An animal reserve has 28,000 elk. The population is at a rate of 15% per year. How long will it take for the population to reach 56,000?

Answer: In 5 years time the population will reach to 56,000.

Step-by-step explanation:

This can be calculated using yearly compound interest formula

Formula for yearly compound interest

CI = P (1+R/100) ⁿ

CI = 56,000

P = 28,000

R = 15%

n = number of years

Now,

56,000 = 28,000 (1+15/100) ⁿ

56,000 = 28,000 (1+.15) ⁿ = 28,000 (1.15) ⁿ

log (56,000/28,000) = n log (1.15)

log 2 = n log (1.15)

n = log 2/log 1.15

n≅ 5