Data sufficiency

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Data sufficiency

by jeyachandar » Thu Feb 02, 2012 2:28 am
Can anyone help me with the question OG 12 Data sufficiency question
If x and y are integers ,is xy even?

1.x = y+1
2.x/y is an even integer

I thought the answer should be B.In choice 1 suppose if y = 0 then the condition xy is even is not satisfied .Hence i felt it cannot be concluded that xy is even Neither we can conclude xy is never even .

Can anyone explain why my assumption is wrong or whats wrong with my thinking?

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by shankar.ashwin » Thu Feb 02, 2012 3:49 am
Hi jeyachandar..

0 is considered an even number.. So (1) will be sufficient as well..

(1) x and y are consecutive integers, one of them will be even.. hence xy is even
(2) Given x/y is even, one of the numbers should be even.. hence product will be even too..
jeyachandar wrote:Can anyone help me with the question OG 12 Data sufficiency question
If x and y are integers ,is xy even?

1.x = y+1
2.x/y is an even integer

I thought the answer should be B.In choice 1 suppose if y = 0 then the condition xy is even is not satisfied .Hence i felt it cannot be concluded that xy is even Neither we can conclude xy is never even .

Can anyone explain why my assumption is wrong or whats wrong with my thinking?

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by Anurag@Gurome » Thu Feb 02, 2012 3:50 am
jeyachandar wrote:Can anyone help me with the question OG 12 Data sufficiency question
If x and y are integers ,is xy even?

1.x = y+1
2.x/y is an even integer

I thought the answer should be B.In choice 1 suppose if y = 0 then the condition xy is even is not satisfied .Hence i felt it cannot be concluded that xy is even Neither we can conclude xy is never even .

Can anyone explain why my assumption is wrong or whats wrong with my thinking?
(1) x = y + 1
If y = 0, x = 1, then xy = 0, which is an even integer.
If y = 1, x = 2, then xy = 2, which is an even integer.
If y = 3, x = 4, then xy = 12, which is an even integer.
Note: 0 is an even integer, not odd.
So, statement 1 is SUFFICIENT.

Hence, the correct answer is D.
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