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# The population of a bacteria culture doubles every 2 minutes

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The population of a bacteria culture doubles every 2 minutes [#permalink]  13 Mar 2008, 19:39
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The population of a bacteria culture doubles every 2 minutes. Approximately how many minutes will it take for the population to grow from 1,000 to 500,000 bacteria

A. 10
B. 12
C. 14
D. 16
E. 18

OPEN DISCUSSION OF THIS QUESTION IS HERE: the-population-of-a-bacteria-culture-doubles-every-2-minutes-167378.html
[Reveal] Spoiler: OA

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Last edited by Bunuel on 25 Jun 2014, 08:49, edited 2 times in total.
Renamed the topic, edited the question, added the OA and moved to PS forum.
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Re: The population of a bacteria culture doubles every 2 minutes [#permalink]  13 Mar 2008, 21:42
Is not quite that.
min 0 - 1,000
min 2 - 2,000=1,000*2^1
min 4 - 4000=1000*2^2;
min 6 - 8000=1000*2^3

Be careful! It doubles every 2 minutes.

So, 1,000*2^x=500,000
2^x=500. It asks you to approx. You know that 2^9=512, so x=9.
Because the pop doubles every 2 minutes, the result=9*2=18 minutes.
OA?
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Re: The population of a bacteria culture doubles every 2 minutes [#permalink]  11 Sep 2013, 17:13
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This one's easy.

1000 * 2^t = 500,000
2^t = 500
Now gauging, since 2^8 = 256, then 2^9 = 512
So t = 9

But be careful, 't' is in time intervals of two minutes

So answer is 9*2 = 18 minutes

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Re: The population of a bacteria culture doubles every 2 minutes [#permalink]  12 Sep 2013, 01:26
Expert's post
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The population of a bacteria culture doubles every 2 minutes. Approximately how many minutes will it take for the population to grow from 1,000 to 500,000 bacteria

A. 10
B. 12
C. 14
D. 16
E. 18

Similar questions to practice:
a-certain-bacteria-colony-doubles-in-size-every-day-for-144013.html
it-takes-30-days-to-fill-a-laboratory-dish-with-bacteria-140269.html
the-number-of-water-lilies-on-a-certain-lake-doubles-every-142858.html
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Math Expert
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Posts: 29205
Followers: 4750

Kudos [?]: 50256 [0], given: 7540

The population of a bacteria culture doubles every 2 minutes [#permalink]  25 Jun 2014, 08:50
Expert's post
The population of a bacteria culture doubles every 2 minutes. Approximately how many minutes will it take for the population to grow from 1,000 to 500,000 bacteria?

(A) 10
(B) 12
(C) 14
(D) 16
(E) 18

$$1000 * 2^t = 500,000$$ --> $$2^t = 500$$ --> since $$2^9 = 512$$, then $$t\approx{9}$$. Thus, approximately 9 two-minute intervals are needed, whcih is 18 minutes.

Similar questions to practice:
a-certain-bacteria-colony-doubles-in-size-every-day-for-144013.html
it-takes-30-days-to-fill-a-laboratory-dish-with-bacteria-140269.html
the-number-of-water-lilies-on-a-certain-lake-doubles-every-142858.html
the-population-of-locusts-in-a-certain-swarm-doubles-every-90353.html

OPEN DISCUSSION OF THIS QUESTION IS HERE: the-population-of-a-bacteria-culture-doubles-every-2-minutes-167378.html
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The population of a bacteria culture doubles every 2 minutes   [#permalink] 25 Jun 2014, 08:50
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