It is currently 15 Dec 2017, 21:43

### 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

# The set S of numbers has the following properties: I) If x

Author Message
Senior Manager
Joined: 21 Aug 2003
Posts: 257

Kudos [?]: 13 [0], given: 0

Location: Bangalore
The set S of numbers has the following properties: I) If x [#permalink]

### Show Tags

09 Nov 2003, 04:10
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.

The set S of numbers has the following properties:
I) If x is in S, then 1/x is in S.
II) If both x and y are in S, then so is x + y.
Is 3 in S?

(1) 1/3 is in S.
(2) 1 is in S.

ps: stolyar, please wait to answer this question before other guys/gals attempt it...

Kudos [?]: 13 [0], given: 0

Manager
Joined: 26 Aug 2003
Posts: 232

Kudos [?]: 13 [0], given: 0

Location: United States

### Show Tags

09 Nov 2003, 16:52
I would say A too.

If we were to consider recursion in the problem then Statement (2) could also give you an answer but that's a different story... n/m

Kudos [?]: 13 [0], given: 0

Senior Manager
Joined: 21 Aug 2003
Posts: 257

Kudos [?]: 13 [0], given: 0

Location: Bangalore

### Show Tags

09 Nov 2003, 19:44
try again... why not D..?
wonder_gmat i think u got the point but why do u still prefer A...?
thanks

Kudos [?]: 13 [0], given: 0

SVP
Joined: 03 Feb 2003
Posts: 1603

Kudos [?]: 312 [0], given: 0

### Show Tags

11 Nov 2003, 00:09
seems like a formal logic question

If A, then B =>
If NOT B, then NOT A.

(1) X=1/3 and it is in S, then 1/X=3 is in S; seems OK, but the conclusion is wrong: If 1/X is in S, then X is in S.

(2) X=1 and it is in S

If there is another 1 in S, then:
Since 1 and 1 are in S, then 1+1=2 is in S.
Since 1, 1, and 2 is in S, then 1+2=3 is in S.
But what if S consists of the only member 1?

D is pretty questionable

Kudos [?]: 312 [0], given: 0

Senior Manager
Joined: 11 Nov 2003
Posts: 356

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

Location: Illinois

### Show Tags

11 Nov 2003, 10:01
I would go for A.

Stolyar,

Are you saying that statement 1 is also not suffecient? I think it is suffecient and I think there is no need to apply the logic rule here. All the statement is saying is that if a number is present in S the inverse of that number is also in S.

I agree with stolyar for the second statement. Not enough.

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

Manager
Joined: 26 Aug 2003
Posts: 232

Kudos [?]: 13 [0], given: 0

Location: United States

### Show Tags

11 Nov 2003, 12:04
Vicky wrote:
try again... why not D..?
wonder_gmat i think u got the point but why do u still prefer A...?
thanks

Vicky,
I would not pick Statement (2) as well because 1 is the one value that does not satisfy both conditions. If it had been anyother number, I would said Statement (2) is also sufficient.

If one is convinced that condition II can be met by still using 1 then the answer would be D, but since 1/1 is the same as 1 itself, it's hard to make this call.

Analysing Statement (2)
Venue 1:
I) If 1 is in S, then 1/1 is in S.
II) If both 1 and 1/1 are in S, then so is 1 + 1/1
Answer: 1 + 1/1 = 2 so now both 1 and 2 are in S so 1 + 2 = 3 is in S.

Venue 2:
I) If 1 is in S, then 1/1 = 1 is in S.
II) Can't be met because just '1' is in the set.

Venue 1 will lead us to answer D whereas Venue 2 will so to A. This is my approach at least. But other thoughts are certainly welcome. What was yours, Vicky?

Kudos [?]: 13 [0], given: 0

Intern
Joined: 27 Jul 2003
Posts: 11

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

### Show Tags

17 Nov 2003, 22:58
if 1 is there in the set, automatically it would generate the set of all natural numbers by itself.

Hence D.

Bharathi.

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

GMAT Instructor
Joined: 07 Jul 2003
Posts: 768

Kudos [?]: 243 [0], given: 0

Location: New York NY 10024
Schools: Haas, MFE; Anderson, MBA; USC, MSEE

### Show Tags

18 Nov 2003, 01:23
bhars18 wrote:
if 1 is there in the set, automatically it would generate the set of all natural numbers by itself.

Hence D.

Bharathi.

I agree. "X" and "Y" are just variables. IMO, there is no reason why two variables cannot have the same value.
_________________

Best,

AkamaiBrah
Former Senior Instructor, Manhattan GMAT and VeritasPrep
Vice President, Midtown NYC Investment Bank, Structured Finance IT
MFE, Haas School of Business, UC Berkeley, Class of 2005
MBA, Anderson School of Management, UCLA, Class of 1993

Kudos [?]: 243 [0], given: 0

Manager
Joined: 04 Jun 2003
Posts: 61

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

### Show Tags

19 Nov 2003, 19:32
I'd vote for D.
(1) is definitely sufficient coz 3 and 1/3 are mutually existed.

But
For me, to (2), I think people normally write an only member of specific set once(one time is enough).
thus S = {1}
That means we cannot reach the value for 3. THEREFORE: SUFFICIENT

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

CEO
Joined: 15 Aug 2003
Posts: 3452

Kudos [?]: 928 [0], given: 781

### Show Tags

23 Nov 2003, 14:52
ann wrote:

vicks , you have an explanation for this one

Kudos [?]: 928 [0], given: 781

Senior Manager
Joined: 21 Aug 2003
Posts: 257

Kudos [?]: 13 [0], given: 0

Location: Bangalore

### Show Tags

23 Nov 2003, 19:30
If this question appears at GMAT.
i wud chose D, which also happens to be the Official answer.
Akamai's point is worth noting.
thanks

Kudos [?]: 13 [0], given: 0

CEO
Joined: 15 Aug 2003
Posts: 3452

Kudos [?]: 928 [0], given: 781

### Show Tags

23 Nov 2003, 19:56
Vicky wrote:
If this question appears at GMAT.
i wud chose D, which also happens to be the Official answer.
Akamai's point is worth noting.
thanks

i did not understand akamai's explanation.

A is sufficient..isnt it .. its a YES

B ... is it a YES or NO?

thanks

Kudos [?]: 928 [0], given: 781

Director
Joined: 14 Oct 2003
Posts: 582

Kudos [?]: 59 [0], given: 0

Location: On Vacation at My Crawford, Texas Ranch

### Show Tags

25 Nov 2003, 20:57
Vicky wrote:
If this question appears at GMAT.
i wud chose D, which also happens to be the Official answer.
Akamai's point is worth noting.
thanks

Okay, WHY would you choose D if you saw this on the actual GMAT?

Kudos [?]: 59 [0], given: 0

25 Nov 2003, 20:57
Display posts from previous: Sort by

# The set S of numbers has the following properties: I) If x

 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®.