Number Properties

Expert replies

pareekbharat86: Master | Next Rank: 500 Posts; Posts: 168; Joined: Thu Nov 01, 2012 7:43 pm; Thanked: 1 times

by pareekbharat86 » Sat Nov 23, 2013 7:47 am

If n is an integer, is n even?
(1) n*n âˆ’1 is an odd integer.
(2) 3n + 4 is an even integer.

OA is D

0, an integer, satisfies both statements. Yet, we know 0 is neither positive nor negative. Why D?

I think I am missing a point here. Please help.

Thanks,
Bharat.

Like this post

Source: Beat The GMAT — Data Sufficiency | Sat Nov 23, 2013 7:47 am

GMAT/MBA Expert

Brent@GMATPrepNow: GMAT Instructor; Posts: 16207; Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members; Location: Vancouver, BC; Thanked: 5254 times; GMAT Score:770

by Brent@GMATPrepNow » Sat Nov 23, 2013 7:51 am

If n is an integer, is n even?
(1) nÂ² âˆ’ 1 is an odd integer.
(2) 3n + 4 is an even integer.

Target question: Is n even?

Statement 1: nÂ² âˆ’ 1 is an odd integer.
If nÂ² âˆ’1 is an odd integer, then nÂ² must be an even integer.
If nÂ² is an even integer, then n must be even.
Rationale: (odd)Â² = odd, but (even)Â² = even
As such, statement 1 is SUFFICIENT

Statement 2: 3n + 4 is an even integer.
If 3n + 4 is an even integer, then 3n must be an even integer (since Even + Even = Even).
If 3n must be an even integer, then n must be even.
Rationale: (odd)(even) = even and
As such, statement 2 is SUFFICIENT

Answer = D

Cheers,
Brent

Brent Hanneson - Creator of GMATPrepNow.com

Like this post

GMAT/MBA Expert

Brent@GMATPrepNow: GMAT Instructor; Posts: 16207; Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members; Location: Vancouver, BC; Thanked: 5254 times; GMAT Score:770

by Brent@GMATPrepNow » Sat Nov 23, 2013 7:53 am

pareekbharat86 wrote: 0, an integer, satisfies both statements. Yet, we know 0 is neither positive nor negative. Why D?

You're right, 0 is neither positive nor negative
However, the question isn't asking whether n is positive or negative. It's asking whether n is even.
0 is even

Cheers,
Brent

Brent Hanneson - Creator of GMATPrepNow.com

Like this post

dominhtri1995: Senior | Next Rank: 100 Posts; Posts: 61; Joined: Sat Aug 17, 2013 8:53 am; Thanked: 10 times

by dominhtri1995 » Sat Nov 23, 2013 7:53 am

Hi ,

We are asked whether n is even?

NOT positive or negative

You should take a rest man

))

Regard,

Like this post

pareekbharat86: Master | Next Rank: 500 Posts; Posts: 168; Joined: Thu Nov 01, 2012 7:43 pm; Thanked: 1 times

by pareekbharat86 » Sat Nov 23, 2013 7:59 am

dominhtri1995 wrote:Hi ,

We are asked whether n is even?

NOT positive or negative

You should take a rest man ))

Regard,

ya man, its saturday night and I have put 70 hours of work already

Cheers!

Thanks,
Bharat.

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review