posted by .

A culture contains 12,000 bacteria. After an hour the count is 25,000. Find the number of bacteria after 3 hours.

  • Math -

    let's assume the growth of bacteria is "almost" continuous
    so number = initial value e^(kt) where k is a constant

    so 12000 e^(1k) = 25000
    e^k = 2.0833333...
    k = ln 2.083333.. =.733969

    number after 3 hrs = 12000 e^(3(.733969)) = 108506.9 or
    109,000 to the nearest thousand

Respond to this Question

First Name

School Subject

Your Answer

Similar Questions

  1. precalculus

    A bacteria culture initially contains 1500 bacteria and doubles every half hour. a) Find an expression for the number of bacteria after t hours. Q(t)= b) The number of bacteria after 20 minutes is (the answer must be an integer) c) …
  2. Calc

    The number of bacteria in a culture is increasing according to the law of exponential growth. There are 125 bacteria in the culture after 2 hours and 350 bacteria after 4 hours. a) Find the initial population. b) Write an exponential …
  3. MATH :)

    3. In Biology, it is found that the bacteria in a certain culture double every half-hour. If the initial number of bacteria in culture is 1000, A. Find the defining equation for the number N of bacteria in culture after T hours, assuming …
  4. Algebra 2

    If there are initially 1500 bacteria in a culture, and the number of bacteria double each hour, the number of bacteria after t hours can be found using the formula N=1500(2^t). How many bacteria will present after 7 hours?
  5. calculus

    2. The rate of change in the number of bacteria in a culture is proportional to the number present. In a certain laboratory experiment, a culture has 10,000 bacterial initially, 20,000 bacteria at time t1 minutes, and 100,000 bacteria …
  6. Pre-Calc/Trig...

    is this the correct formula for me to solve this?
  7. Urgent math

    population growth model. Can anybody please help me out in trying to solve this problem?
  8. math

    A culture starts with 8300 bacteria. After one hour the count is 10,000. (a) Find a function that models the number of bacteria n(t) after t hours. (Round your r value to three decimal places.)
  9. PreCalc

    The initial size of a culture of bacteria is 1500. After 1 hour the bacteria count is 12000. (a) Find a function n(t) = n0e^rt that models the population after t hours. (Round your r value to five decimal places.) n(t) = (b) Find the …
  10. Algebra

    A certain culture initially contains 10,000 bacteria and increase by 20% after every hour. A) What will be the formula for numbers N(t) of bacteria after "t" hours?

More Similar Questions