Find all School-related info fast with the new School-Specific MBA Forum

It is currently 19 May 2013, 19:06
Customize  |  Hide

http://www.manhattangmat.com

  Question banks Downloads My Bookmarks Reviews  
Author Message
TAGS:
Director
Director
User avatar
Joined: 05 May 2003
Posts: 560
Location: Aus
Followers: 2

Kudos [?]: 3 [0], given: 0

GMAT Tests User
http://www.manhattangmat.com [#permalink] New post 12 Jan 2004, 10:06
Kaplan Promo CodeKnewton GMAT Discount CodesGMAT Pill GMAT Discount Codes
Intern
Intern
Joined: 13 Jan 2004
Posts: 8
Location: Right here
Followers: 0

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

MGMAT Q of the week [#permalink] New post 13 Jan 2004, 05:49
If P^a x Q^b x R^c x S^d is a perfect square than each prime factor that divides this number divides it an even number of times.

If P,Q,R and S are primes, they could be distinct only if all of - a,b,c and d were even. Otherwise some of P,Q,R and S would have to be the same so that the odd numbers out of a,b,c and d could combine to form an even exponent.

So...

(1) if 18 is a factor of both ab and cd we know nothing - a,b,c and d could all be either even or odd, and we haven't a clue.

(2) If 4 is not a factor of ab nor cd, then we know that it CANNOT be that both a and b are even (if that were the case - ab would be divisible by 4), and that it cannot be that both c and d are even (same reason).

So at least two out of a,b,c and d are odd, and therefore not all of P,Q,R and S can be distinct if the above number if a perfect square.

Final answer - B
MGMAT Q of the week   [#permalink] 13 Jan 2004, 05:49
    Similar topics Author Replies Last post
Similar
Topics:
New posts http://www.manhattangmat.com Geethu 4 23 Feb 2004, 08:27
Popular new posts http://www.manhattangmat.com Geethu 12 15 Mar 2004, 08:06
New posts http://www.manhattangmat.com Geethu 6 22 Mar 2004, 08:25
New posts source: http://www.manhattangmat.com thearch 8 13 Jun 2005, 11:10
New posts source: http://gmatquantproblems.blogspot.com bhushan252 1 05 Oct 2009, 00:08
Display posts from previous: Sort by

http://www.manhattangmat.com

  Question banks Downloads My Bookmarks Reviews  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.