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Is Y even?

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by pharmxanthan » Thu May 06, 2010 6:31 pm
I think that the answer is B.
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by neerajkumar1_1 » Thu May 06, 2010 6:33 pm
pharmxanthan wrote:I think that the answer is B.
Cant be B, as sqrt(6) or any other sqrt(x), will give u a incorrect answer
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by debmalya_dutta » Thu May 06, 2010 6:45 pm
1. even (2)* even = even and even (2)*odd = even => not sufficient
2. even * even = even => the fact that y^2 is even means y is even => sufficient

Hence B
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by liferocks » Thu May 06, 2010 7:33 pm
From 1
2Y is even-->Y can be even or odd..not sufficient

from 2

Y^2 is even -->if Y is either even or irrational number like sqrt(8),sqrt(10) etc....not sufficient

combining
since 2Y is even Y is an integer.

hence from 2 we are left with only one option that Y is even

Ans option C..together statements are sufficient

can you please provide the QA

also this is a DS question.Please post DS questions under DS folder.
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by neerajkumar1_1 » Thu May 06, 2010 8:31 pm
liferocks wrote:From 1
2Y is even-->Y can be even or odd..not sufficient

from 2

Y^2 is even -->if Y is either even or irrational number like sqrt(8),sqrt(10) etc....not sufficient

combining
since 2Y is even Y is an integer.

hence from 2 we are left with only one option that Y is even

Ans option C..together statements are sufficient

can you please provide the QA

also this is a DS question.Please post DS questions under DS folder.
The OA is C... My only question, how do u deduce that y is an integer, with 2Y even, Y can be anything right ???
My Mistake with the wrong thread.... :)
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by liferocks » Fri May 07, 2010 2:08 am
neerajkumar1_1 wrote:
liferocks wrote:From 1
2Y is even-->Y can be even or odd..not sufficient

from 2

Y^2 is even -->if Y is either even or irrational number like sqrt(8),sqrt(10) etc....not sufficient

combining
since 2Y is even Y is an integer.

hence from 2 we are left with only one option that Y is even

Ans option C..together statements are sufficient

can you please provide the QA

also this is a DS question.Please post DS questions under DS folder.
The OA is C... My only question, how do u deduce that y is an integer, with 2Y even, Y can be anything right ???
My Mistake with the wrong thread.... :)
from 2 we have 2 options
Y is even
Y is irrational..if this is true 2Y will also be irrational as if we multiply a rational number with irrational result will be irrational.
but as per 1 2Y is integer
hence Y is not irrational...
only option left is Y is even
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by neerajkumar1_1 » Fri May 07, 2010 4:02 am
Please explain how the first statement proves that Y is an integer ???
thanks...
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by sanju09 » Fri May 07, 2010 4:21 am
neerajkumar1_1 wrote:Is Y even?
(1) 2Y is even.
(2) Y^2 is even.

I figured the answer is E.

Please let me know your answers.
When we write even/odd for numbers, we mean integers.

(1) If 2 Y is even, Y is an integer, that's it. Is it even or odd, result unknown. insufficient

(2) If Y^2 is even, Y could be either irrational or an even. Insufficient

Taken together

(1) says Y is an integer, and (2) says that Y could be either irrational or an even. Since an integer cannot be irrational, hence, [spoiler]YES, Y is even.

C[/spoiler]
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by sanju09 » Fri May 07, 2010 4:24 am
neerajkumar1_1 wrote:Please explain how the first statement proves that Y is an integer ???
thanks...
If 2 Y is even, then take any even number for 2 Y, divide it by 2. Are you getting an integer or what else?
The mind is everything. What you think you become. -Lord Buddha



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