A certain population of bacteria doubles every 10 minutes.

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Source: — Data Sufficiency |

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by Brent@GMATPrepNow » Thu Dec 19, 2019 6:16 am
swerve wrote:A certain population of bacteria doubles every 10 minutes. If the number of bacteria in the population initially was 10^4, what was the number in the population 1 hour later?

A. 2(10^4)
B. 6(10^4)
C. (2^6)(10^4)
D. (10^6)(10^4)
E. (10^4)^6

The OA is C

Source: Official Guide
Let's list some populations and look for a pattern

Initial population: 10�
10 minutes later: (10�)(2)
20 minutes later: (10�)(2)(2)
30 minutes later: (10�)(2)(2)(2)
40 minutes later: (10�)(2)(2)(2)(2)
50 minutes later: (10�)(2)(2)(2)(2)(2)
60 minutes later: (10�)(2)(2)(2)(2)(2)(2) = (10�)(2�)

Answer: C

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Brent
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by Scott@TargetTestPrep » Thu Dec 26, 2019 8:19 pm
swerve wrote:A certain population of bacteria doubles every 10 minutes. If the number of bacteria in the population initially was 10^4, what was the number in the population 1 hour later?

A. 2(10^4)
B. 6(10^4)
C. (2^6)(10^4)
D. (10^6)(10^4)
E. (10^4)^6

The OA is C

Source: Official Guide
Since one hour has 6 ten-minute intervals, after one hour the population is 10^4 x 2^6.

Answer: C

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