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

 It is currently 30 Jun 2016, 17:58

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

this is from one of the 'hard math' princeton pdf's and i

Author Message
Joined: 31 Dec 1969
Location: India
Concentration: Marketing, General Management
GMAT 1: 710 Q49 V0
GMAT 2: 700 Q V
GMAT 3: 740 Q40 V50
GMAT 4: 700 Q48 V38
GMAT 5: 710 Q45 V41
GMAT 6: 680 Q47 V36
GMAT 7: Q42 V44
GMAT 8: Q42 V44
GMAT 9: 740 Q49 V42
GMAT 10: 740 Q V
GMAT 11: 500 Q47 V33
GPA: 3.3
WE: Sales (Investment Banking)
Followers: 0

Kudos [?]: 151 [0], given: 97736

this is from one of the 'hard math' princeton pdf's and i [#permalink]

Show Tags

05 Sep 2004, 22:00
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.

this is from one of the 'hard math' princeton pdf's and i think their answer is wrong.

18. If x , y , and z are integers, is x / ( yz ) an integer?
(1) y is a factor of x more than once.
(2) All of the prime factors of z are also
factors of y .

My answer and theirs are below, PAGE DOWN a few times to see...

Manager
Joined: 05 Sep 2004
Posts: 97
Followers: 1

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

Show Tags

06 Sep 2004, 00:49
I agree with Princeton's answer. Why do you think it's wrong or E?
Joined: 31 Dec 1969
Location: India
Concentration: Marketing, General Management
GMAT 1: 710 Q49 V0
GMAT 2: 700 Q V
GMAT 3: 740 Q40 V50
GMAT 4: 700 Q48 V38
GMAT 5: 710 Q45 V41
GMAT 6: 680 Q47 V36
GMAT 7: Q42 V44
GMAT 8: Q42 V44
GMAT 9: 740 Q49 V42
GMAT 10: 740 Q V
GMAT 11: 500 Q47 V33
GPA: 3.3
WE: Sales (Investment Banking)
Followers: 0

Kudos [?]: 151 [0], given: 97736

Show Tags

06 Sep 2004, 07:20
y = 2 ^ 2 * 3 = 12
z = 2 * 3 ^ 3 = 54

x = y * y = 2916
y * z = 648

and yet, (zy) does not divide x, 2916 / 648 is not an integer.

the way i am reading it is, all the prime factors of z are factors of y. so 2 and 3 are factors of y, but not necessarily 3 ^ 3.
Manager
Joined: 05 Sep 2004
Posts: 97
Followers: 1

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

Show Tags

06 Sep 2004, 10:24
user wrote:
y = 2 ^ 2 * 3 = 12
z = 2 * 3 ^ 3 = 54

x = y * y = 2916
y * z = 648

and yet, (zy) does not divide x, 2916 / 648 is not an integer.

the way i am reading it is, all the prime factors of z are factors of y. so 2 and 3 are factors of y, but not necessarily 3 ^ 3.

The way I read the question, I get that ALL the prime factors of z have to be factors of y. Therefore, if 3 happens to occur twice in z, then it must occur twice in y.
Director
Joined: 20 Jul 2004
Posts: 593
Followers: 2

Kudos [?]: 93 [0], given: 0

Show Tags

06 Sep 2004, 10:44
I think user is correct in the assumption on Prime factors. Otherwise, they would just be called factors. I support E too.
Btw, user, you might have meant, x = y * y = 144

The ans for the above example, x=144 y=12 z=54, is "No, x/yz is not an integet"
The ans for another example, x=25 y=5 z=5, is " "Yes, x/yz is an integer".
Hence, E.
Senior Manager
Joined: 19 May 2004
Posts: 291
Followers: 1

Kudos [?]: 11 [0], given: 0

Show Tags

06 Sep 2004, 10:51
Agree with E.
Same reasons as user.
Manager
Joined: 05 Sep 2004
Posts: 97
Followers: 1

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

Show Tags

06 Sep 2004, 11:21
hardworker_indian wrote:
I think user is correct in the assumption on Prime factors. Otherwise, they would just be called factors.

The reason they use prime factors in case of z and just factors in case of y is that if you don't do that, you'll be explicitly stating that y and z are the same numbers.

It's just a matter of semantics. Questions on the actual GMAT are usually not this ambigious.
Director
Joined: 31 Aug 2004
Posts: 610
Followers: 3

Kudos [?]: 96 [0], given: 0

Show Tags

06 Sep 2004, 14:17

http://www.gmatclub.com/phpbb/viewtopic.php?t=9471

Display posts from previous: Sort by