It is currently 21 Feb 2018, 01:01

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

if y is an integer, is y^3 divisible by 9? 1) y is divisible

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Director
Director
avatar
Joined: 23 May 2008
Posts: 799
if y is an integer, is y^3 divisible by 9? 1) y is divisible [#permalink]

Show Tags

New post 29 Sep 2008, 21:11
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

if y is an integer, is y^3 divisible by 9?

1) y is divisible by 4
2) y is divisible by 6
Senior Manager
Senior Manager
User avatar
Joined: 29 Mar 2008
Posts: 348
Re: from veritas prep [#permalink]

Show Tags

New post 29 Sep 2008, 21:24
if y is an integer, is y^3 divisible by 9?

1) y is divisible by 4
2) y is divisible by 6

ST1) Y can be 4 or 24. When Y is 4, Y^3 is not divisible by 9. When Y is 24, Y^3 is divisible by 9. Hence, Insuff.
ST2) Since 6 is a multiple of 3, Y^3 should be divisible by 9 (or 3^2). Eg, when y= 6, 12, 18..., Y^3 is divisible by 9.Hence Suff.

Ans: (B)
_________________

To find what you seek in the road of life, the best proverb of all is that which says:
"Leave no stone unturned."
-Edward Bulwer Lytton

Director
Director
avatar
Joined: 23 May 2008
Posts: 799
Re: from veritas prep [#permalink]

Show Tags

New post 29 Sep 2008, 21:28
yes, B

i figured out why though,

1) you can get 12^3 which is divisible by both 9 and 4
becase 12^3 = 4x3x4x3x4x3 or you can get 4^3 =4x4x4, not divisible by 9 so insufficient

2) if divisible by 6 then y^3 has to be at least 3x2x3x2x3x2, which is always divisible by 9 since there are three 3's
SVP
SVP
avatar
Joined: 17 Jun 2008
Posts: 1529
Re: from veritas prep [#permalink]

Show Tags

New post 29 Sep 2008, 21:29
B.

From stmt1: y = 4a for a = 0,1,2,3,.....

for any values of a other than multiple of 3, y^3 will not be divisible by 9 whereas for values of a that are multiple of 3, y^3 will be divisible by 9. Hence, insufficient.

From stmt2: y = 6a = 3*2*a for a = 0,1,2,3..... and for any values of a y^3 will be divisible by 9. Hence, sufficient.
Re: from veritas prep   [#permalink] 29 Sep 2008, 21:29
Display posts from previous: Sort by

if y is an integer, is y^3 divisible by 9? 1) y is divisible

  post reply Question banks Downloads My Bookmarks Reviews Important topics  

Moderator: chetan2u



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

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

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®.