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Number Properties

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Number Properties

by pareekbharat86 » Sat Nov 23, 2013 7:47 am
If n is an integer, is n even?
(1) n*n −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.
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by Brent@GMATPrepNow » Sat Nov 23, 2013 7:51 am
If n is an integer, is n even?
(1) n² − 1 is an odd integer.
(2) 3n + 4 is an even integer.
Target question: Is n even?

Statement 1: n² − 1 is an odd integer.
If n² −1 is an odd integer, then n² must be an even integer.
If n² is an even integer, then n must be even.
Rationale: (odd)² = odd, but (even)² = 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

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Brent
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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
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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,
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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.
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