og-ds of m

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og-ds of m

by pradeepkaushal9518 » Sat Aug 28, 2010 11:23 pm
if m is an integer,is m odd?

1.m/2 is not an even integer
2.m-3 is an even integer
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by sirisha.g » Sat Aug 28, 2010 11:30 pm
IMO B.
because statement 1 says m/2 is not an even integer => m/2 might be even integer(10/2) or might not be an integer at all(5/2). so will get even and odd number satisfying this condition. hence not sufficient.( correct me if i am wrong)

statement 2 gives a direct answer odd-odd=even. hence sufficient

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by thirst4edu » Sun Aug 29, 2010 12:43 pm
pradeepkaushal9518 wrote:if m is an integer,is m odd?

1.m/2 is not an even integer
2.m-3 is an even integer
IMO D

Given that m is an integer.

stmt 1) m/2 is not an even integer. To get m/2 as non integer, m has to be odd integer. Hence, sufficient.

stmt 2) (m-3) is an even integer.

EVEN +- ODD = ODD and ODD +- ODD=EVEN, Hence m should be odd. Sufficient.
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by Rahul@gurome » Sun Aug 29, 2010 3:13 pm
pradeepkaushal9518 wrote:if m is an integer,is m odd?

1.m/2 is not an even integer
2.m-3 is an even integer
(1) m/2 is not an even integer.
If m = 14, then m/2 = 7, which is odd.
If m = 7, then m/2 = decimal.
We don't get a unique answer.

So, (1) is NOT SUFFICIENT.

(2) m - 3 is an even integer implies m has to be odd, as Odd - odd = even.
Therefore, m is odd.

So, (2) is SUFFICIENT.

The correct answer is [spoiler](B)[/spoiler].
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by thirst4edu » Sun Aug 29, 2010 3:19 pm
Rahul@gurome wrote:
pradeepkaushal9518 wrote:if m is an integer,is m odd?

1.m/2 is not an even integer
2.m-3 is an even integer
(1) m/2 is not an even integer.
If m = 14, then m/2 = 7, which is odd.
If m = 7, then m/2 = decimal.
We don't get a unique answer.

So, (1) is NOT SUFFICIENT.

(2) m - 3 is an even integer implies m has to be odd, as Odd - odd = even.
Therefore, m is odd.

So, (2) is SUFFICIENT.

The correct answer is [spoiler](B)[/spoiler].

Ahh I always make similar mistake of reading non-even integer as not integer.. Thanks Rahul !
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