Questions about the world of GMAT Math from other sources and general math related questions.
rajkoneru
 
 

Math Q

by rajkoneru Mon Oct 01, 2007 10:48 pm

Can you please let me know the solution for this with explaination.Thanks

If n is a positive integer and r is the remainder when (n-1)(n+1) is divided by 24, what is
the value of r?
(1) 2 is not a factor of n.
(2) 3 is not a factor of n.
Guest
 
 

Re: Math Q

by Guest Mon Oct 01, 2007 10:53 pm

rajkoneru Wrote:Can you please let me know the solution for this with explaination.Thanks

If n is a positive integer and r is the remainder when (n-1)(n+1) is divided by 24, what is
the value of r?
(1) 2 is not a factor of n.
(2) 3 is not a factor of n.


This is a SETS Question.
shaji
 
 

Re: Math Q

by shaji Wed Oct 03, 2007 11:57 pm

(n-1)(n+1)=n^2-1( A perfect square less 1) is always divisible by 24 when n has neither 2 and 3 as factors.

The correct answr is C.

rajkoneru Wrote:Can you please let me know the solution for this with explaination.Thanks

If n is a positive integer and r is the remainder when (n-1)(n+1) is divided by 24, what is
the value of r?
(1) 2 is not a factor of n.
(2) 3 is not a factor of n.
RonPurewal
Students
 
Posts: 19744
Joined: Tue Aug 14, 2007 8:23 am
 

by RonPurewal Fri Oct 12, 2007 5:02 am

Please POST A SOURCE for each question that you post - book, question # (or, if it's from GMATPrep or an online CAT, then the first few words of the problem statement).

Thanks.