Question

a population of 550 rabbits is increasing by 7.5% each year. in about how many years will the population be over 1000?
a) about 5 years
b) about 9 years
c)about 15 years
d)about 7 years

Answer 1

I believe this would take the form of an exponential equation:

A = Ao (1 + r)^t

where A is final population, Ao is initial population, r is rate of growth and t is time

 

A / Ao = (1 + r)^t

log A / Ao = t log (1 + r)

t = (log A / Ao) / log (1 + r)

t = [log (1000 / 550)] / log (1.075)

t = 8.27 years

 

SO the answer is B) about 9 years