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Is x even? (1) x^5 is even. (2) 4x – 2 is even.

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Bunuel
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Is x even? (1) x^5 is even. (2) 4x – 2 is even. [#permalink] New post   23 Jan 2017, 09:30
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Is x even?

(1) x^5 is even.
(2) 4x – 2 is even.
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C
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rohit8865
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Is x even? (1) x^5 is even. (2) 4x – 2 is even. [#permalink] New post   24 Jan 2017, 11:26
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Bunuel wrote:
Is x even?

(1) x^5 is even.
(2) 4x – 2 is even.



(1) if x= 2^1/5 then X^5= 2 thus x is not even
IF x=2 then x^5=32 thus X is even

Not suff

(2) if x=3 then 4x – 2 = 10 even thus x =odd
if x=2 then 4x – 2 = 6 even thus x=even
Not suff

combining both
we know x must be integer
thus from (1) x must be even(as odd^x = odd)

Ans C
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Is x even? (1) x^5 is even. (2) 4x – 2 is even. [#permalink] New post   25 Jan 2018, 21:58
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Bunuel wrote:
Is x even?

(1) x^5 is even.
(2) 4x – 2 is even.


With almost 100% going wrong in a sub-600 level question shows that we tend to overlook number properties at many times..
(1) \(x^5\) is even.
If x is an integer, yes x is even..
But if x is not an integer
\(x=\sqrt[5]{2}\).. \(x^5 is even but x is NOT\\
Insuff\)

(2) \(4x – 2\) is even
\(4x-2=2(2x-1)\)
so x could be any integer, 1,2, or even fraction 1.5,2.5...
insuff

combined..
statement II gives x as an integer and statement I says if x is integer, x is even..
sufficient

C
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Re: Is x even? (1) x^5 is even. (2) 4x – 2 is even. [#permalink] New post   23 Jan 2017, 10:04
A) is the answer.

As 2) will always be even regardless of the value of x so it's not sufficient IMO

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Re: Is x even? (1) x^5 is even. (2) 4x – 2 is even. [#permalink] New post   25 Jan 2018, 23:06
1-Since x is not necessarily an integer, then it is easy to prove x could either be even (2^5 = 32, but (2^(1/5))^5 = 2, but x is not even
Not suff

2- 4x-2 is even. X could be even (2) or x could not be even (i.e. 0.5)
Not suff

1,2 combined will be satisfied since x would have to be an integer in this case... then C will be the answer

Great question!!!!!


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RahulHGGmat
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Re: Is x even? (1) x^5 is even. (2) 4x – 2 is even. [#permalink] New post   19 Oct 2021, 00:23
chetan2u wrote:
Bunuel wrote:
Is x even?

(1) x^5 is even.
(2) 4x – 2 is even.


With almost 100% going wrong in a sub-600 level question shows that we tend to overlook number properties at many times..
(1) \(x^5\) is even.
If x is an integer, yes x is even..
But if x is not an integer
\(x=\sqrt[5]{2}\).. \(x^5 is even but x is NOT\\
Insuff\)

(2) \(4x – 2\) is even
\(4x-2=2(2x-1)\)
so x could be any integer, 1,2, or even fraction 1.5,2.5...
insuff

combined..
statement II gives x as an integer and statement I says if x is integer, x is even..
sufficient

C


Hi Chetan2u,

You have mentioned that second statement specify that x must be integer. However this is not necessary as if we put x = 1/2, then also question we get the result as even number. Then how C can be the answer of this question
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RahulHGGmat
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Re: Is x even? (1) x^5 is even. (2) 4x – 2 is even. [#permalink] New post   19 Oct 2021, 00:25
Hi Bunuel Sajjad1994 chetan2u

request you to provide a detailed solution to this question.
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Re: Is x even? (1) x^5 is even. (2) 4x 2 is even. [#permalink] New post   20 Apr 2024, 06:49
Hello from the GMAT Club BumpBot!

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Re: Is x even? (1) x^5 is even. (2) 4x 2 is even. [#permalink]
20 Apr 2024, 06:49
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