If k is a positive integer, is k the square of an integer? : DS Archive
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 22 Jan 2017, 14:36

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# If k is a positive integer, is k the square of an integer?

Author Message
Intern
Joined: 14 Jun 2005
Posts: 37
Followers: 1

Kudos [?]: 5 [0], given: 0

If k is a positive integer, is k the square of an integer? [#permalink]

### Show Tags

23 Sep 2005, 21:43
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If k is a positive integer, is k the square of an integer?

(1) k is divisible by 4.

(2) k is divisible by exactly 4 different prime numbers.
Senior Manager
Joined: 30 Oct 2004
Posts: 284
Followers: 1

Kudos [?]: 62 [0], given: 0

### Show Tags

24 Sep 2005, 05:50
IMO (B) is suff to prove K is NOT a square of an integer.
_________________

-Vikram

Senior Manager
Joined: 04 May 2005
Posts: 282
Location: CA, USA
Followers: 1

Kudos [?]: 51 [0], given: 0

### Show Tags

24 Sep 2005, 08:37
tingle wrote:
(2) k is divisible by exactly 4 different prime numbers.

Not sure what this means ? - k divisible by 2, 3, 5, 7 for example,
then it is also divisible by 6,15,35, 4, 9, 25, 49 etc. what is "exactly" ?
Senior Manager
Joined: 13 Jan 2005
Posts: 331
Followers: 1

Kudos [?]: 2 [0], given: 12

### Show Tags

26 Sep 2005, 09:00
I think its a E. May be I am reading too much into it.

A - Not suff (K could be 16 or 8)
B - K= Eg.: 2^a X 3^b X 5^c X 7 ^d

If a=b=c=d=1, then K is exactly divisble by 4 diff prime numbers. K cannot be a square
But a=b=c=d=2 then K is still divisible by 4 diff prime numbers. K can be a square in this case

Hence B not suff

C - not suff as well a=2, but doesn't say much abt b, c, and d

Hence E.

GA
Current Student
Joined: 28 Dec 2004
Posts: 3384
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 15

Kudos [?]: 282 [0], given: 2

### Show Tags

26 Sep 2005, 09:16
B for me

Prime^even power is always perfect square...

Prime^odd power not a perfect square...

(II) tells that there are only 4 prime factors

which I read as they only appear once! which means Prime^1 is not going to lead to a perfect square...

if I read exactly (II) incorrectly, and there can be more than one appeareance of prime factors then E is the right answer..
Intern
Joined: 27 Aug 2005
Posts: 33
Followers: 0

Kudos [?]: 2 [0], given: 0

### Show Tags

26 Sep 2005, 10:21
The rule states that, for all the perfect squares, the number of prime factors are always odd..

and for all the non perfect square numbers, the number of prime factors are always even.

My answer is (B) because we get to know that K is not a perfect square number
26 Sep 2005, 10:21
Display posts from previous: Sort by