Wednesday

November 26, 2014

November 26, 2014

Posted by **Riana** on Sunday, December 23, 2012 at 1:35am.

a) if four doses of the antibiotic are taken, what percent of the original bacterial population is left.

b) biologists have determined that when a person has a bacterial infection, if the bacterial level can be reduced to 5% of its population, the person can fight off the infection. How many doses must be administered to reduce the bacterial population to the desired level?

Its a geometric question.

- math -
**drwls**, Sunday, December 23, 2012 at 2:58ama) (0.9)^4 = 0.656 = 65.6% of original remains

b) Solve (0.9)^N = 0.05 for N

N = log(0.05)/log(0.9]= 28.4

- math -
**Riana**, Sunday, December 23, 2012 at 7:33pmIts shud be done without using log

- math -
**MathMate**, Tuesday, December 25, 2012 at 11:03amWithout log, you only have to multiply 1.0 by 0.9 as many times as need to get a product of 0.05. I get 0.052 after multiplying 28 times and 0.047 after multiplying 29 times.

So the answer is between 28 to 29 doses.

**Answer this Question**

**Related Questions**

math - a certain antibiotic redues the number of bacteria in your body by 10% ...

Math(geometric sequences) - A certain antibiotic reduces the number of bacteria ...

PreCalculus - 2000(1 – 0.75) = 2000 (.25) = 500 survivors after the dose of ...

PreCalc - 2000(1 – 0.75) = 2000 (.25) = 500 survivors after the dose of ...

Pre Calculus - When doctors prescribe medicine at equally spaced time intervals...

Public Financial Management - Analyze the following scenario: The Hospital for ...

Math - I'm not sure how to do this question 7. The growth of bacteria in culture...

calculus - 2. The rate of change in the number of bacteria in a culture is ...

Health (Ms. Sue) - Describe how bacteria develop antibiotic diseases. A: ...

Math - I was thinking that I have to multiply but that doesn't make sense. ...