Exponential and Logarithmic Models

Question

A bacteria culture initially contains 2500 bacteria and doubles every half hour.

Find the size of the bacterial population after 60 minutes.   

Find the size of the bacterial population after 4 hours

Answer 1

initial amount 2500 doubling time = 1/2 hour

how much after 60 minutes = 1 hr?? after 4 hrs??

after 60 minutes that's 2/1/2 = 2 doublings = 2500 x 2^2 = 10,000

after 4 hours that's 4/1/2 = 8 doublings = 2500 x 2^8 = 2500 x 128 = 320,000