Divisibility and prime

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Source: — Data Sufficiency |

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by gmat_dest » Thu Jul 23, 2009 7:46 am
1. Pick Q= 11 and 2.

-----> Not sufficient

2. Did algebraic calculation. 2Q/11 is an integer so that *2 = another integer

B is sufficient.

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by ogbeni » Thu Jul 23, 2009 7:48 am
C because
Statement 1: Q could be 2, 3, 5, 7, 11, 19 - so eliminate
Statmeent 2: Q could be 11 or -11 and the questions asks if 4Q/11 is POSITIVE therefore eliminate
Combining both statements we know a prime number must be POSITIVE therefore 11x4/Q = positive integer

Trick question!!! ha ha ha

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by hk » Thu Jul 23, 2009 7:49 am
gmat_dest wrote:1. Pick Q= 11 and 2.

-----> Not sufficient

2. Did algebraic calculation. 2Q/11 is an integer so that *2 = another integer

B is sufficient.
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by hk » Thu Jul 23, 2009 7:50 am
ogbeni wrote:C because
Statement 1: Q could be 2, 3, 5, 7, 11, 19 - so eliminate
Statmeent 2: Q could be 11 or -11 and the questions asks if 4Q/11 is POSITIVE therefore eliminate
Combining both statements we know a prime number must be POSITIVE therefore 11x4/Q = positive integer

Trick question!!! ha ha ha
You got it!!!! OA is C
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