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Bacteria in a petri dish doubles every 10 minutes. (Express in exponential function)

a) If there are 10 bacteria initially, how many are there after 120 minutes?

b) If there are 10 bacteria initially, when would there be a million bacteria?

User Sinuhepop
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1 Answer

2 votes

Answer:

a)1280 bacteria

Explanation:

We find the function in t hours first

Bacteria in a petri dish doubles every 10 minutes. (Express in exponential function)

a) If there are 10 bacteria initially, how many are there after 120 minutes?

b) If there are 10 bacteria initially, when would there be a million bacteria?

The formula to use is given as

y = Ab^t

Where

y = Total Population of bacteria

B= initial population of the bacteria

r =

t = time in hours

The bacteria doubles in the petri dish every 10 minutes, we have 10 bacteria

10 minutes in hours = 10/60= 1/6 hours

10 × 2 = 10b^10/60

20 = 10b ^1/6

2 = b^1/6

Multiply both sides by Power of 6

2^6 = b

b = 64

Hence, y = 10×(64)^t

a) If there are 10 bacteria initially, how many are there after 120 minutes?

120 minutes in hours = 2

y = 10(64)²

y = 1280

There would be 1280 bacteria after 120 minutes

b) If there are 10 bacteria initially, when would there be a million bacteria?

y= 1,000,000

A = 10 bacteria

b = 64

t = ???

1000000 = 10 × (64)^t

Divide both sides by 10

100000 = (64)^t

User Theycallmemorty
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