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

It is currently 25 Oct 2014, 02:45

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If a number is drawn at random from the first 1000 positive

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Current Student
User avatar
Joined: 29 Jan 2005
Posts: 5252
Followers: 23

Kudos [?]: 140 [0], given: 0

Reviews Badge
If a number is drawn at random from the first 1000 positive [#permalink] New post 23 Nov 2005, 06:19
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

24% (01:05) correct 76% (00:58) wrong based on 45 sessions
If a number is drawn at random from the first 1000 positive integers, what is the probability of selecting a refined number?

(1) Any refined number must be divisible by 22
(2) A refined number is any even multiple of 11
[Reveal] Spoiler: OA
Manager
Manager
avatar
Joined: 15 Aug 2005
Posts: 137
Followers: 2

Kudos [?]: 7 [0], given: 0

Re: DS PGMAT (probability) [#permalink] New post 23 Nov 2005, 07:13
GMATT73 wrote:
If a number is drawn at random from the first 1000 positive integers, what is the probability of selecting a refined number?

1. Any refined number must be divisible by 22
2. A refined number is any even multiple of 11


I think it should be D

1. you can find the number of numbers divisible by 22 and less than 1000 ----> sufficient

2. you can find the number of numbers divisible by 11 and less than 1000 ----> sufficient
Current Student
User avatar
Joined: 29 Jan 2005
Posts: 5252
Followers: 23

Kudos [?]: 140 [0], given: 0

Reviews Badge
 [#permalink] New post 23 Nov 2005, 20:49
Sorry guys, OA is not D. Any other guesses?
VP
VP
avatar
Joined: 06 Jun 2004
Posts: 1061
Location: CA
Followers: 2

Kudos [?]: 29 [0], given: 0

 [#permalink] New post 23 Nov 2005, 21:00
B?

Somehow I think the wordings are a little tricky.........
Current Student
User avatar
Joined: 29 Jan 2005
Posts: 5252
Followers: 23

Kudos [?]: 140 [0], given: 0

Reviews Badge
 [#permalink] New post 24 Nov 2005, 20:07
1. Statement 1 tells us that a refined number must be a multiple of 22. This is a necessary, but not sufficient condition for a refined number. While every refined number is a multiple of 22, every multiple of 22 is not necessarily a refined number. Since we have no other info about the definition of a refined number, we cannot determine how many integers from 1-1000 fit that definition. Insuff.

2. Statement 2 provides us with a definition of a refined number- an even multiple of 11. We can find the number of even multiples of 11 in the set, so this is sufficient.

OA is (B)
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jul 2004
Posts: 5095
Location: Singapore
Followers: 19

Kudos [?]: 155 [0], given: 0

 [#permalink] New post 25 Nov 2005, 00:23
GMATT73 wrote:
1. Statement 1 tells us that a refined number must be a multiple of 22. This is a necessary, but not sufficient condition for a refined number. While every refined number is a multiple of 22, every multiple of 22 is not necessarily a refined number. Since we have no other info about the definition of a refined number, we cannot determine how many integers from 1-1000 fit that definition. Insuff.

2. Statement 2 provides us with a definition of a refined number- an even multiple of 11. We can find the number of even multiples of 11 in the set, so this is sufficient.

OA is (B)


Isn't (2) just a repetition of (1)?
(2) says the refined number must be an even multiple of 11. So a refined number can be 22, 44, 66, 88, 110,... etc... All these are multiples off 22, which is given in (1).
Manager
Manager
avatar
Joined: 15 Aug 2005
Posts: 137
Followers: 2

Kudos [?]: 7 [0], given: 0

 [#permalink] New post 27 Nov 2005, 08:38
GMATT73 wrote:
1. Statement 1 tells us that a refined number must be a multiple of 22. This is a necessary, but not sufficient condition for a refined number. While every refined number is a multiple of 22, every multiple of 22 is not necessarily a refined number. Since we have no other info about the definition of a refined number, we cannot determine how many integers from 1-1000 fit that definition. Insuff.

2. Statement 2 provides us with a definition of a refined number- an even multiple of 11. We can find the number of even multiples of 11 in the set, so this is sufficient.

OA is (B)


GMATT73 I see the point.
..this question has a very good trap.
Manager
Manager
avatar
Joined: 21 Mar 2005
Posts: 115
Location: Basel
Followers: 1

Kudos [?]: 4 [0], given: 0

 [#permalink] New post 27 Nov 2005, 10:39
good question. I think it is B. I is just a condition but does not define refined numbers.
Current Student
avatar
Joined: 28 Dec 2004
Posts: 3403
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 13

Kudos [?]: 164 [0], given: 2

 [#permalink] New post 27 Nov 2005, 11:08
what is the point?
I dont get it...(1) and (2) are saying the same thing...I would say such a twisted question will never appear on the GMAT!



believe2 wrote:
GMATT73 wrote:
1. Statement 1 tells us that a refined number must be a multiple of 22. This is a necessary, but not sufficient condition for a refined number. While every refined number is a multiple of 22, every multiple of 22 is not necessarily a refined number. Since we have no other info about the definition of a refined number, we cannot determine how many integers from 1-1000 fit that definition. Insuff.

2. Statement 2 provides us with a definition of a refined number- an even multiple of 11. We can find the number of even multiples of 11 in the set, so this is sufficient.

OA is (B)


GMATT73 I see the point.
..this question has a very good trap.
VP
VP
avatar
Joined: 30 Sep 2004
Posts: 1493
Location: Germany
Followers: 4

Kudos [?]: 52 [0], given: 0

 [#permalink] New post 27 Nov 2005, 11:25
fresinha12 wrote:
what is the point?
I dont get it...(1) and (2) are saying the same thing...I would say such a twisted question will never appear on the GMAT!



believe2 wrote:
GMATT73 wrote:
1. Statement 1 tells us that a refined number must be a multiple of 22. This is a necessary, but not sufficient condition for a refined number. While every refined number is a multiple of 22, every multiple of 22 is not necessarily a refined number. Since we have no other info about the definition of a refined number, we cannot determine how many integers from 1-1000 fit that definition. Insuff.

2. Statement 2 provides us with a definition of a refined number- an even multiple of 11. We can find the number of even multiples of 11 in the set, so this is sufficient.

OA is (B)


GMATT73 I see the point.
..this question has a very good trap.


the diff b/w 1) and 2) is that in 1) 22 and 44 may be refined numbers. we can calc the prob. 22 44 66 may be refinded numbers as well. the prob to the former example is different but both satisfy 1). in 2) its certain that every mutiple off 22 is a refined number. there is only one value for the prob.
_________________

If your mind can conceive it and your heart can believe it, have faith that you can achieve it.

1 KUDOS received
SVP
SVP
User avatar
Joined: 03 Jan 2005
Posts: 2251
Followers: 12

Kudos [?]: 204 [1] , given: 0

 [#permalink] New post 28 Nov 2005, 08:51
1
This post received
KUDOS
fresinha12 wrote:
what is the point?
I dont get it...(1) and (2) are saying the same thing...I would say such a twisted question will never appear on the GMAT!



Yes I've seen this question type in the GMAT test. The trap is (1) doesn't define "refined number" and (2) does.
For example, you can say "an even number must be an integer", this doesn't define an even number, because not every integer is an even number. Similarly with (1), every refined number must be divided by 22. But perhaps they also must be divided by 4, or something else.
_________________

Keep on asking, and it will be given you;
keep on seeking, and you will find;
keep on knocking, and it will be opened to you.

Expert Post
Verbal Forum Moderator
Verbal Forum Moderator
User avatar
Status: Preparing for the another shot...!
Joined: 03 Feb 2011
Posts: 1425
Location: India
Concentration: Finance, Marketing
GPA: 3.75
Followers: 129

Kudos [?]: 648 [0], given: 62

GMAT ToolKit User Premium Member
Re: If a number is drawn at random from the first 1000 positive [#permalink] New post 25 Dec 2012, 06:30
Expert's post
Sorry for starting this old thread, but can anyone please elaborate on this ancient problem? I am still not able to distinguish 1 and 2, apart from considering that one is definition and the other is not. Need examples for clarification.
_________________

Prepositional Phrases Clarified|Elimination of BEING| Absolute Phrases Clarified
Rules For Posting
www.Univ-Scholarships.com

Intern
Intern
avatar
Joined: 20 Dec 2012
Posts: 19
Followers: 0

Kudos [?]: 2 [0], given: 3

Re: If a number is drawn at random from the first 1000 positive [#permalink] New post 25 Dec 2012, 07:12
Marcab wrote:
Sorry for starting this old thread, but can anyone please elaborate on this ancient problem? I am still not able to distinguish 1 and 2, apart from considering that one is definition and the other is not. Need examples for clarification.


I would say it's more about the wording than the math.

Let's make it simple.

1. Any refined number must be divisible by 22

If refined numbers were 44n then (1) would give us wrong numbers. 44, 88, 132 = refined. But (1) doesn't tell us that 22, 44, 110 is not refined.

2. A refined number is any even multiple of 11.

Here we're told the actual definition of refined numbers. They're the even multiples of 11.

11*2
11*4
11*6
and so on.

This doesn't leave any blind spots or confusion.
Intern
Intern
avatar
Joined: 05 Mar 2014
Posts: 5
Followers: 0

Kudos [?]: 0 [0], given: 10

CAT Tests
Re: If a number is drawn at random from the first 1000 positive [#permalink] New post 12 Mar 2014, 22:25
Hello Guys,
This is my first post, I hope you find it helpful.

Now in the question they have asked a no. Is drawn from first 1000 positive integers, and its probability. Def. Of refined no, is given in respective statements. Its all about wordings.

Now,
S1.) Any refined no must be divisible by 22, this include 22, 44, 242, 110, 198,.... and the list goes on, there are definite nos. and nos can be found, but the statement says ANY, which is absurd.
INSUFFICIENT.

S2.) A refined no is any even multiple of 11. This includes 22, 44, 66, 88, 286,484, 968..... and on, here also no can be found but A REFINED NO. IS MENTIONED. This makes it clear a definite no particularly even multiple of 11.
SUFFICIENT.
BASICALLY ITS ALL ON WORDING, YOU DONT NEED TO SOLVE.

ANS B.


WHAT YOU THINK, YOU BECOME.
Re: If a number is drawn at random from the first 1000 positive   [#permalink] 12 Mar 2014, 22:25
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic 2 cards are drawn at random medanova 1 19 Dec 2010, 09:02
3 marbles are drawn at random from a bag containing 3 red asaf 2 29 Sep 2006, 09:09
Two cards are drawn at random from a pack of 52 cards. Find remgeo 6 22 Nov 2005, 06:26
A number is selected at random from the set of integers{ cloaked_vessel 4 25 Sep 2005, 08:20
If a number is drawn at random from the first 1000 positive swath20 12 17 Feb 2005, 19:25
Display posts from previous: Sort by

If a number is drawn at random from the first 1000 positive

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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®.