bacteria

  1. R

    The number of bacteria initially in a culture is 4,518 . If the number increases at..

    The number of bacteria initially in a culture is 4,518 . If the number increases at the continuous hourly rate of 5.32 %, how many bacteria will be present at the end of 13 hours? Count only whole bacteria. Please explain. Thank you!
  2. M

    Bacteria growth!

    My tutor is growing bacteria. She starting off with a mass of 150 grams of bacteria at 12 pm on tuesday, than every hour the mass of bacteria is growing by 15%, but my tutor wants to end up with 3 grams of bacteria. Should I use a computer or calculator on my level of precision and why should...
  3. S

    Help with floor function involving bacteria?

    I know how to figure this question out if there is a ending amount of hours (such as how many bacteria will be there at the end of 8 hours), but when there is a floor function thrown in there I have no clue how to solve this or where to start. Any help would be appreciated. The floor function...
  4. A

    Infectious Bacteria

    An infection strain of bacteria increases in number at a relative growth rate of 200% per hour. When a certain critical number of bacteria are present in the bloodstream, a person becomes ill. If a single bacterium infects a person, the critical level is reached in 24 hours. How long will it...
  5. F

    Find Bacteria After x Hours

    If bacteria double in number every hour, how many bacteria will there be after x hours? Start with 1 bacteria? MY WORK: Let B = bacteria Is the equation B = 2^(x) + 1? Is this correct?
  6. F

    How Many Bacteria After 20 Hours?

    Certain bacteria can double in number in 1 hour. If we start with 1 bacterium, how many bacteria will there be after 20 hours?
  7. F

    Find Number of Bacteria

    If bacteria double in number every hour, how many bacteria will there be after x hours? Start with 1 bacteria?
  8. A

    bacteria problem

    the number of bacteria present in a culture after t minutes is given as B = 1000e^kt. if there are 3448 bacteria present after 7 min...find k
  9. R

    bacteria problem

    At the beginning of an experiment a colony has N bacteria. Two hours later it has 4N bacteria. How many hours, measured from the beginning, does it take for the colony to have 10N bacteria.
  10. W

    Exponential Bacteria

    Suppose that a bacterial culture is growing exponentially and the culture doubles every 12 hours. Obtain a formula for the number Pn of square millimeters of culture expected in n hours given that the culture measured 5 square millimeters when first observed.
  11. R

    doubling bacteria

    A bacteria culture starts with 800 bacteria and doubles in size every half hour. I have already found the formula to be: f(x)=800(2)^{2t} I just am having trouble doing this question... (d) Graph the population function and estimate the time for the population to reach 70,000. (Give your...
  12. A

    Bacteria and martingale

    Let N_n, n\geq 1 be the size of a population of bacteria at time step n. At each step each bacteria produces a number of offspring and dies. The number of offspring is independent for each bacteria and is distributed according to the Poisson law with parameter \lambda = 2. Assuming that...
  13. S

    (exponents) bacteria growh

    If a bacteria population doubles in 7 days, when was it half of its present population? so the equation would be A = A0 (1+i)^n where A = final population where A0 = initial population where i = 100% (because it doubles) so 1 where n = the amount of time it occurs but since you're not given A...
  14. M

    The no. of bacteria...

    The number of bacteria in a culture has been doubling every four hours and is currently 380000.How fast is the bacteria population growing right now,in terms of number of bacteria per hour?
  15. W

    Did I do this bacteria growth problem correctly?

    A certain type of bacteria increases continuously at a rate proportional to the number present. if there are 500 bacteria at a given time and 1000 present 2 hours later, how many will there be 5 hours from the initial time given? dP/dt = kP dP=kPdt ∫dP/P = k ∫dt ln|P| = kt + C P = Ce^kt P=...
  16. A

    Bacteria Decay Help, Thank You in Advance

    A bacteria culture starts with 140 bacteria and grows at a rate proportional to its size. After 5 hours there will be 700 bacteria. Express the population after t hours as a function of t. population: I just don't really understand the wording and how it might look. Thank you,
  17. S

    Bacteria Growth Problem

    A bacteria culture initially contains P(o) cells and grows at the rate dP/dt = kP where k is a growth constant. After an hour the population has doubled. (a) Determine an expression for the number of bacteria present after t hours. (b) Computer the number of bacteria present, and the rate of...
  18. E

    [SOLVED] Bacteria Growth

    How is this done? Is there a formula? I missed class, and I need step by step help on how these type problems are solved. THANK YOU A colony of bacteria being grown in a jog of apple cider is known to triple every 5 hours. We know that the number of bacteria at 8 a.m. was 6000. How many...
  19. J

    Bacteria doubling

    I have a exponential function problem. A population of 500 E. coli bacteria doubles every 15 minutes. Use this information to find an expression for this population growth. Using this expression, find what the population would be in 87 minutes. Use an exponential model. I set up a table to...
  20. M

    Exponential Growth (Bacteria)

    A culture starts with 680 bacteria. after 30 minutes the count is 3250. find a formula for the number of bacteria after t hours. after how many minutes, rounded to the nearest minute, will the bacteria triple? what i have: n(t) = n(o)e^rt 3250 = 680e^30r im not sure what to do after, can...