GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 16 Oct 2019, 11:02

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

If x is an integer greater than 1, is x equal to 2^k for

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Senior Manager
Senior Manager
avatar
Status: Up again.
Joined: 31 Oct 2010
Posts: 464
Concentration: Strategy, Operations
GMAT 1: 710 Q48 V40
GMAT 2: 740 Q49 V42
If x is an integer greater than 1, is x equal to 2^k for  [#permalink]

Show Tags

New post 09 Jan 2011, 01:33
1
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

52% (01:36) correct 48% (01:37) wrong based on 77 sessions

HideShow timer Statistics

If x is an integer greater than 1, is x equal to 2^k for some positive integer k?

(1) x has only one prime factor.
(2) Every factor of x is even.

Can anyone please explain the statements to me?

Statement 1 says x has only one prime factor. Am I to assume that x is a prime number? or am i to assume that x is a number such as 9, whose only prime factor is 3. Or the number can be 2,3... its confusing to me,

Statement 2 says every factor of x is even. Does such a number exist?

Source: Jeff Sackmann's questions

_________________
My GMAT debrief: http://gmatclub.com/forum/from-620-to-710-my-gmat-journey-114437.html
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58381
Re: If x is an integer greater than 1, is x equal to 2^k for  [#permalink]

Show Tags

New post 09 Jan 2011, 04:07
1
gmatpapa wrote:
If x is an integer greater than 1, is x equal to \(2^k\) for some positive integer k?
(1) x has only one prime factor.
(2) Every factor of x is even.

Can anyone please explain the statements to me?

Statement 1 says x has only one prime factor. Am I to assume that x is a prime number? or am i to assume that x is a number such as 9, whose only prime factor is 3. Or the number can be 2,3... its confusing to me,

Statement 2 says every factor of x is even. Does such a number exist?

Source: Jeff Sackmann's questions


If x is an integer greater than 1, is x equal to 2^k for some positive integer k?

Basically question ask whether x is some power of 2: 2 (for k=1), 4 (for k=2), 8 (for k=3), ...

(1) x has only one prime factor --> x can be ANY prime in ANY positive integer power: 2, 2^3, 3, 3^7, 5, 5^2, ... Note that all this numbers have only one prime factor. Not sufficient.

(2) Every factor of x is even --> this statement makes no sense, every positive integer has at least one positive odd factor: 1. I think it should be: x has no odd factor more than 1 (or: every factor of x, except 1, is even). In this case as x don't have any odd factors >1 then x has no odd primes in its prime factorization --> x is of the form of 2^k for some positive integer k. Sufficient.

Answer: B.

Not a good question.
_________________
Senior Manager
Senior Manager
avatar
Status: Up again.
Joined: 31 Oct 2010
Posts: 464
Concentration: Strategy, Operations
GMAT 1: 710 Q48 V40
GMAT 2: 740 Q49 V42
Re: If x is an integer greater than 1, is x equal to 2^k for  [#permalink]

Show Tags

New post 09 Jan 2011, 05:06
Bunuel wrote:
gmatpapa wrote:
If x is an integer greater than 1, is x equal to \(2^k\) for some positive integer k?
(1) x has only one prime factor.
(2) Every factor of x is even.

Can anyone please explain the statements to me?

Statement 1 says x has only one prime factor. Am I to assume that x is a prime number? or am i to assume that x is a number such as 9, whose only prime factor is 3. Or the number can be 2,3... its confusing to me,

Statement 2 says every factor of x is even. Does such a number exist?

Source: Jeff Sackmann's questions


If x is an integer greater than 1, is x equal to 2^k for some positive integer k?

Basically question ask whether x is some power of 2: 2 (for k=1), 4 (for k=2), 8 (for k=3), ...

(1) x has only one prime factor --> x can be ANY prime in ANY positive integer power: 2, 2^3, 3, 3^7, 5, 5^2, ... Note that all this numbers have only one prime factor. Not sufficient.

(2) Every factor of x is even --> this statement makes no sense, every positive integer has at least one positive odd factor: 1. I think it should be: x has no odd factor more than 1 (or: every factor of x, except 1, is even). In this case as x don't have any odd factors >1 then x has no odd primes in its prime factorization --> x is of the form of 2^k for some positive integer k. Sufficient.

Answer: B.

Not a good question.


Yes. if statement 2 is rephrased as you said, it will be a sufficient statement. I think this what even the question maker had in mind but it slipped off his mind somehow. I will mail him to correct this.

Thanks Bunuel!
_________________
My GMAT debrief: http://gmatclub.com/forum/from-620-to-710-my-gmat-journey-114437.html
Intern
Intern
avatar
Joined: 21 Nov 2012
Posts: 1
GMAT ToolKit User
If x is an integer greater than 1  [#permalink]

Show Tags

New post 09 Jan 2018, 18:58
If x is an integer greater than 1, is x equal to 2^k
for some positive integer k?
(1) x has only one prime factor.
(2) Every factor of x is even.


Source: Jeff Sackman
Math Expert
avatar
V
Joined: 02 Aug 2009
Posts: 7959
Re: If x is an integer greater than 1  [#permalink]

Show Tags

New post 09 Jan 2018, 20:20
Soniab wrote:
If x is an integer greater than 1, is x equal to 2^k
for some positive integer k?
(1) x has only one prime factor.
(2) Every factor of x is even.


Source: Jeff Sackman


x>1, is x=2^k

1) x has only one prime factor..
So x could be 2,2^k, 3,3^k,5^k...
Insuff

2) every factor of x is even...
Only possible when x=2*2*2.....
So yes x=2^k
Sufficient

B
_________________
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58381
Re: If x is an integer greater than 1, is x equal to 2^k for  [#permalink]

Show Tags

New post 09 Jan 2018, 20:56
GMAT Club Bot
Re: If x is an integer greater than 1, is x equal to 2^k for   [#permalink] 09 Jan 2018, 20:56
Display posts from previous: Sort by

If x is an integer greater than 1, is x equal to 2^k for

  post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne