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by sam2304 » Wed Jan 04, 2012 10:59 pm
What does the second statement imply |X!| - how different is it from X! ?

Is it E ?

Here goes my explanation

Statement 1:
X! not divisible by 5 => then X is less than 5, i.e 4!, 3! So INSUFF as 4 is not a prime integer and 3 is a prime integer.

Statement 2:
|X!| is divisible by 6 => then X>=3 3! is divisible by 6, 4! is divisible by 6. Again INSUFF.

Combining 1 & 2 Both 3! and 4! fit the criteria so INSUFF

IMO E. Hope its right.
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by karthikpandian19 » Thu Jan 05, 2012 8:39 pm
OA is E
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by pemdas » Thu Jan 05, 2012 8:47 pm
why this question has mode in st(2)?

what's the source?
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by karthikpandian19 » Fri Jan 06, 2012 4:14 am
the SOURCE is MASTER GMAT - Quans Section
pemdas wrote:why this question has mode in st(2)?

what's the source?
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by Abhishek009 » Fri Jan 06, 2012 9:28 am
karthikpandian19 wrote:Is X a prime integer?
(1) X! is not divisible by 5
(2) |X!| is divisible by 6
X! is not divisible by 5 , so x must be less than 5...

Let's take 4..

Now x! will be 4! => 4*3*2*1

Let's check if it's divisible by 6 - Yes ( 3 *2 makes it possible for division by 6 ) it's possible..


Now take any other number less than 5

Say we take 3..

Now 3! is 3*2*1

This is not divisible by 5 , but is completely divisible by 6..


So , in my opinion we can't predict if X is a prime number or not...
Abhishek
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