If y ≠ 3 and 3x/y is a prime integer greater than 2, : Quant Question Archive [LOCKED]
Check GMAT Club App Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 08 Dec 2016, 12:01

### 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 y ≠ 3 and 3x/y is a prime integer greater than 2,

Author Message
Manager
Joined: 29 Jul 2007
Posts: 182
Followers: 1

Kudos [?]: 30 [0], given: 0

If y ≠ 3 and 3x/y is a prime integer greater than 2, [#permalink]

### Show Tags

26 Nov 2007, 14:57
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If y ≠ 3 and 3x/y is a prime integer greater than 2, which of the following must be true?
Ⅰ. x = y
Ⅱ. y = 1
Ⅲ. x and y are prime integers.

A) None
B) Ⅰ only
C) Ⅱ only
D) Ⅲ only
E) Ⅰ and Ⅲ
CEO
Joined: 17 Nov 2007
Posts: 3589
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 530

Kudos [?]: 3455 [0], given: 360

### Show Tags

26 Nov 2007, 15:05
B.

1. if x<y> 3*n - is not a prime. so x=y. suff.
2. for (1,1) y=1 but for (2,2) y=2 insuff.
3. for (2,2) x,y - prime but for (4,4) x,y - not prime. insuff.
SVP
Joined: 29 Aug 2007
Posts: 2492
Followers: 67

Kudos [?]: 729 [0], given: 19

### Show Tags

26 Nov 2007, 15:07
Skewed wrote:
If y ≠ 3 and 3x/y is a prime integer greater than 2, which of the following must be true?
Ⅰ. x = y
Ⅱ. y = 1
Ⅲ. x and y are prime integers.

A) None
B) Ⅰ only
C) Ⅱ only
D) Ⅲ only
E) Ⅰ and Ⅲ

must be!!! hmmm.................

ok, then it is B. I only because if x and y are cancelled out then only 3x/y remains a prime.
Manager
Joined: 29 Jul 2007
Posts: 182
Followers: 1

Kudos [?]: 30 [0], given: 0

### Show Tags

26 Nov 2007, 15:24
What about [(5/3),1] for x,y in case I?

[3*(5/3)]/1= 5

A.
SVP
Joined: 29 Aug 2007
Posts: 2492
Followers: 67

Kudos [?]: 729 [0], given: 19

### Show Tags

26 Nov 2007, 16:25
Skewed wrote:
What about [(5/3),1] for x,y in case I?

[3*(5/3)]/1= 5

A.

thats why the question says that y is not equal to 3.

though thats a good point.
CEO
Joined: 17 Nov 2007
Posts: 3589
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 530

Kudos [?]: 3455 [0], given: 360

### Show Tags

26 Nov 2007, 16:28
hm... A is reasonably.
Intern
Joined: 26 Nov 2007
Posts: 1
Followers: 0

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

### Show Tags

26 Nov 2007, 16:31
Skewed wrote:
What about [(5/3),1] for x,y in case I?

[3*(5/3)]/1= 5

A.

In case I, Y has to be equal to X.
CEO
Joined: 29 Mar 2007
Posts: 2583
Followers: 19

Kudos [?]: 409 [0], given: 0

### Show Tags

26 Nov 2007, 16:32
Skewed wrote:
What about [(5/3),1] for x,y in case I?

[3*(5/3)]/1= 5

A.

Thats pretty good.

Tiger he says that (3*5/3)/1 X=5/3. So A looks good.
Director
Joined: 22 Aug 2007
Posts: 567
Followers: 1

Kudos [?]: 50 [0], given: 0

### Show Tags

26 Nov 2007, 16:33
B it is,

was going to say E..
Director
Joined: 22 Aug 2007
Posts: 567
Followers: 1

Kudos [?]: 50 [0], given: 0

### Show Tags

26 Nov 2007, 16:37
GMATBLACKBELT wrote:
Skewed wrote:
What about [(5/3),1] for x,y in case I?

[3*(5/3)]/1= 5

A.

Thats pretty good.

Tiger he says that (3*5/3)/1 X=5/3. So A looks good.

from the question:

3x=y*prime number-----> either y=3 or prime number=3

y is not 3, thus Prime number= 3----> 3x=y3---->x=y, where x and y are not necessarily prime numbers.
Manager
Affiliations: CFA L3 Candidate, Grad w/ Highest Honors
Joined: 03 Nov 2007
Posts: 130
Location: USA
Schools: Chicago Booth R2 (WL), Wharton R2 w/ int, Kellogg R2 w/ int
WE 1: Global Operations (Futures & Portfolio Financing) - Hedge Fund ($10bn+ Multi-Strat) WE 2: Investment Analyst (Credit strategies) - Fund of Hedge Fund ($10bn+ Multi-Strat)
Followers: 1

Kudos [?]: 102 [0], given: 9

### Show Tags

26 Nov 2007, 17:59

Ⅱ only!
Senior Manager
Joined: 06 Aug 2007
Posts: 368
Followers: 1

Kudos [?]: 34 [0], given: 0

### Show Tags

26 Nov 2007, 18:05
Skewed wrote:
What about [(5/3),1] for x,y in case I?

[3*(5/3)]/1= 5

A.

Good point was going for B..
Director
Joined: 22 Aug 2007
Posts: 567
Followers: 1

Kudos [?]: 50 [0], given: 0

### Show Tags

26 Nov 2007, 18:22
Skewed wrote:
What about [(5/3),1] for x,y in case I?

[3*(5/3)]/1= 5

A.

it was not mentioned that x is an intenger...missed this point

vote for A
Senior Manager
Joined: 09 Oct 2007
Posts: 466
Followers: 1

Kudos [?]: 42 [0], given: 1

### Show Tags

26 Nov 2007, 19:06
agh! the simple ones...

how do one avoid felling for these tricks?
Director
Joined: 22 Aug 2007
Posts: 567
Followers: 1

Kudos [?]: 50 [0], given: 0

### Show Tags

26 Nov 2007, 19:17
asdert wrote:
agh! the simple ones...

how do one avoid felling for these tricks?

"assumed to be possible unless stated or proved otherwise"

unless it says that a number is not a ratio, same as to say that a number is an intenger (as in the example above), we can correctly assume that the number is a ratio ..

simple indeed,

i fell for too
Intern
Joined: 25 Nov 2007
Posts: 38
Followers: 0

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

### Show Tags

27 Nov 2007, 06:17
It is A.

x=1/3
Y=1/5

3x/y = 5 which is prime

so x != y
SVP
Joined: 05 Jul 2006
Posts: 1683
Followers: 6

Kudos [?]: 297 [0], given: 49

### Show Tags

27 Nov 2007, 11:49
If y ≠ 3 and 3x/y is a prime integer greater than 2, which of the following must be true?
Ⅰ. x = y
Ⅱ. y = 1
Ⅲ. x and y are prime integers

for 3x/y to be prime , x/y must = 1

i believe it is A
SVP
Joined: 28 Dec 2005
Posts: 1575
Followers: 3

Kudos [?]: 144 [0], given: 2

### Show Tags

16 Dec 2007, 08:38
did we get a final consensus on this one ?

I am getting A. Here is why.

Q basically tells us that 3x/y =3,5,7,9, ...

1 says x must equal y. not true, because if 3x/y=5, we just get 3x=5y. not always true

2 says y must be 1. again, from above, we can see it doesnt have to be the case.

3. x and y must be prime. i dont think they do, just by looking at the above.

so since none fit the bill, i went with A
Manager
Joined: 11 Aug 2007
Posts: 64
Followers: 1

Kudos [?]: 15 [0], given: 0

### Show Tags

16 Dec 2007, 08:56
it is obviously A:

Pick numbers: x=14, y=6
3*14/6=7. None of the choices works. And no restrictions on x=14 and y=6
Re: prime integer   [#permalink] 16 Dec 2007, 08:56
Display posts from previous: Sort by