A population is modelled by , where is in years. After how many years, to one decimal place, will the population first reach 600?

Answer and explanation

Correct answer: C. 22.0 years

  1. Step 1: Set , so .
  2. Step 2: Take natural logs: .
  3. Step 3: years.
Answer
22.0 years.
Why not the others: 20.0 years assumes a linear model; 13.9 years uses for a doubling; 60.0 years divides 600 by 10.

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