Science:Math Exam Resources/Courses/MATH110/December 2014/Question 08 (a)
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Question 08 (a) 

Assume that the number of bacteria at time (in minutes) follows an exponential growth model , where and are constant. Suppose the count in the bacteria culture was 300 after 15 minutes and 1800 after 40 minutes. You may leave your answers unsimplified, i.e. in "calculatorready" form. (a) What was the initial size of the culture? 
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Hint 

Find the constant by using the given information. 
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Solution 

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Please rate my easiness! It's quick and helps everyone guide their studies. Since the count in the bacteria culture was 300 after 15 minutes and 1800 after 40 minutes, this means and . This implies that and . Then dividing by , we get Solving , we get and hence . Plugging this back into the equation , we can find . Therefore, the initial size of culture . 