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If Z is an integer, is Z prime?
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07 Mar 2012, 11:51
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64% (00:57) correct 36% (01:14) wrong based on 454 sessions
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If Z is an integer, is Z prime? (1) 15! < Z (2) 17! + 2 < Z < 17! + 17
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If Z is an integer, is Z prime?
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07 Mar 2012, 12:01




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Re: If Z is an integer, is Z prime?
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12 Jun 2013, 04:27



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Re: If Z is an integer, is Z prime?
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08 Jan 2014, 03:25
If the statement B was rephrased to ===> 17! + 2 < Z < 17! + 19 then will the answer to this question change to E ?



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Re: If Z is an integer, is Z prime?
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09 Nov 2014, 11:03
For the above question, this will help (its a matched question and all the posts there make things clearer) ifxisanintegerdoesxhaveafactornsuchthat regards



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Re: If Z is an integer, is Z prime?
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15 Nov 2016, 09:02
I read the Kaplan explanation and read explanations above in the thread and I can't find a clue.... For instance, why 17!+13 is equal to 13∗(2∗4∗5∗6∗7∗8∗9∗10∗11∗12∗14∗15∗16∗17+1)? Isn't (2∗4∗5∗6∗7∗8∗9∗10∗11∗12∗14∗15∗16∗17+1) = 17!? So, why 17! multiplied by 13 would be equal to 17! + 13?



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Re: If Z is an integer, is Z prime?
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15 Nov 2016, 09:08



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Re: If Z is an integer, is Z prime?
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15 Nov 2016, 09:30
Ok, now I can see.. But honestly, it is kind of hard question for somebody who did not specialize in math...



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Re: If Z is an integer, is Z prime?
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02 May 2017, 07:20
Amazing question & Amazing explanation by Bunuel!
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Re: If Z is an integer, is Z prime?
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25 Aug 2018, 06:39
Bunuel wrote: If Z is an integer, is Z prime?(1) \(15!<z\) > \(z\) is more than some number (\(15!\)). \(z\) may or may not be a prime. Not sufficient. (2) \(17!+2\leq{z}\leq{17!+17}\) > \(z\) cannot be a prime. For instance if \(z=17!+13=13*(2*3*4*5*6*7*8*9*10*11*12*14*15*16*17+1)\), then \(z\) is a multiple of 13, so not a prime. Same for all other numbers in this range. So, \(z=17!+x\), where \(2\leq{x}\leq{17}\) will definitely be a multiple of \(x\) (as we would be able to factor out \(x\) out of \(17!+x\), the same way as we did for 13). Sufficient. Answer: B. Similar questions to practice: http://gmatclub.com/forum/ifxisanin ... 00670.htmlhttp://gmatclub.com/forum/doestheinte ... 26735.htmlHope it's clear. Bunuel can you please give similar example (with factoring out number) where Z is prime number ?
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Re: If Z is an integer, is Z prime?
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26 Aug 2018, 04:01




Re: If Z is an integer, is Z prime? &nbs
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