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

 It is currently 05 Jul 2015, 00:54

### 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

# what is the probab of selecting a " clean" number from a set

Author Message
TAGS:
Manager
Joined: 25 Oct 2004
Posts: 249
Followers: 1

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

what is the probab of selecting a " clean" number from a set [#permalink]  18 Feb 2005, 08:00
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
what is the probab of selecting a " clean" number from a set of integers containing all multiples of 3 between 1 and 99, inclusive?

(1) A " clean" no is an integer divisible only by 2 factors, one of which is greater than 2

(2) A " clean" no must be odd
Manager
Joined: 15 Feb 2005
Posts: 246
Location: Rockville
Followers: 1

Kudos [?]: 6 [0], given: 0

I am gonna go off on a limb and chose A
because all multiples of 3 are not odd 3,6,9,12
and 3*1 works; 2*3 will also work....terefore negating statement two
(A)
Manager
Joined: 25 Oct 2004
Posts: 249
Followers: 1

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

Could you elaborate why stmt 2 is insuff.....I am lost.....
Manager
Joined: 15 Feb 2005
Posts: 246
Location: Rockville
Followers: 1

Kudos [?]: 6 [0], given: 0

Statement 2 is in sufficient cause it would mean that the clean numbers are 3, 5,7...
statement 1 shows that it is 3,5, 6,7..
does that show why there is at least 1 non odd number?
Senior Manager
Joined: 30 Dec 2004
Posts: 296
Location: California
Followers: 1

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

The question is:
what is the probab of selecting a " clean" number from a set of integers containing all multiples of 3 between 1 and 99, inclusive?

So in my opinion all you need is a definition of what a clean number is. From both statements you can get a definite number of integers that fulfill the criterion mentioned...so therfore I think the answer is D.

And statement 2 should be sufficient because all you have to do is pick the odd number which are multiples of 3 and divide them by all the odd numbers between 1 and 99...don't see why that isn't sufficient
_________________

"No! Try not. Do. Or do not. There is no try.

Manager
Joined: 13 Feb 2005
Posts: 63
Location: Lahore, Pakistan
Followers: 1

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

greenandwise wrote:

The question is:
what is the probab of selecting a " clean" number from a set of integers containing all multiples of 3 between 1 and 99, inclusive?

So in my opinion all you need is a definition of what a clean number is. From both statements you can get a definite number of integers that fulfill the criterion mentioned...so therfore I think the answer is D.

And statement 2 should be sufficient because all you have to do is pick the odd number which are multiples of 3 and divide them by all the odd numbers between 1 and 99...don't see why that isn't sufficient

definitely, i agree with u my man...the basic object is to find 'probability' not 'validity'
Intern
Joined: 17 Feb 2005
Posts: 28
Location: SE Michigan
Followers: 0

Kudos [?]: 14 [0], given: 0

This question is similar to another one posted here somewhere. Statement 1 gives a complete (in itself) definition of a clean number whereas Statement 2 only describes what could be one of many attributes of a clean no.

A it is!
Director
Joined: 19 Nov 2004
Posts: 563
Location: SF Bay Area, USA
Followers: 3

Kudos [?]: 75 [0], given: 0

The set is clearly defined. Whatever the restrictions the statements 1 and 2 impose, we can still find a single probability. So it is D

Note: If the set were infinite, we can't find a probability.

EDIT:
On rethink - A is probably it.
Statement 2 does not clearly define a Clean number.
A clean number must be odd does not imply all odd numbers are clean numbers.
VP
Joined: 25 Nov 2004
Posts: 1494
Followers: 6

Kudos [?]: 40 [0], given: 0

Re: DS-probab-multiples [#permalink]  19 Feb 2005, 21:52
swath20 wrote:
what is the probab of selecting a " clean" number from a set of integers containing all multiples of 3 between 1 and 99, inclusive?

(1) A " clean" no is an integer divisible only by 2 factors, one of which is greater than 2
(2) A " clean" no must be odd

using each statement seperately, both are suff to ans independently. but if you, take stat 1 into consideration 2 seems incomplete. we know that a clean number is only 3 and each st must give a specific answer. therefore, OA should be A. however, we cannot totaly disagree with the other part of the discussions.
Senior Manager
Joined: 19 Feb 2005
Posts: 486
Location: Milan Italy
Followers: 1

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

MA wrote:
thearch wrote:
IMO, That's right!

IMO=?

In my opinion
Senior Manager
Joined: 02 Feb 2004
Posts: 345
Followers: 1

Kudos [?]: 26 [0], given: 0

Re: DS-probab-multiples [#permalink]  23 Feb 2005, 08:13
swath20 wrote:
what is the probab of selecting a " clean" number from a set of integers containing all multiples of 3 between 1 and 99, inclusive?

(1) A " clean" no is an integer divisible only by 2 factors, one of which is greater than 2

(2) A " clean" no must be odd

wait a second....
6 is divisible exactly by two factors ( I assume factors don't include 1 or the number itself) 2 and 3, but it's not odd.

So we need B.

SVP
Joined: 03 Jan 2005
Posts: 2246
Followers: 13

Kudos [?]: 226 [0], given: 0

Re: DS-probab-multiples [#permalink]  23 Feb 2005, 09:04
swath20 wrote:
what is the probab of selecting a " clean" number from a set of integers containing all multiples of 3 between 1 and 99, inclusive?

(1) A " clean" no is an integer divisible only by 2 factors, one of which is greater than 2

(2) A " clean" no must be odd

We are asked to find the probability. We are not asked to find one "clean" number. In other words, as some of the others already mentioned here, as long as the definition is clearly defined, then we will be able to identify all "clean" numbers and thus the probability of pick them from a clearly defined set.

On this note, (1) is clearly define, but (2) is not. (2) would be sufficient if it is formulated like this:
(2) A "clean" number means an odd number.

When it says a clean number must be odd, we do not know if there's other requirements for a clean number. Perhaps it must be odd and greater than 50? Or whatever. As long as we don't know the exact definition of a clean number, we cannot pin down the set of clean numbers, and thus cannot find the probability that we were asked to find.
Manager
Joined: 25 Oct 2004
Posts: 249
Followers: 1

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

Thanks Hong Hu for your detailed explanation
Manager
Joined: 24 Jan 2005
Posts: 217
Location: Boston
Followers: 1

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

Should be D

As there are 33 possible outcomes or numbers.

(1) No of favorable outcomes: all Prime greater than 2 so Probab can be found

(2) favorable outcomes Only odd numbers again Probab can be found
Similar topics Replies Last post
Similar
Topics:
2 What is the probability of selecting a clean number from a s 18 26 Oct 2005, 06:52
If x is to be selected at random from set T, what is the 2 13 Aug 2007, 18:40
If x is to be selected at random from set T, what is the 3 13 Aug 2007, 18:38
If x is to be selected at random from set T, what is the 6 06 Sep 2006, 19:37
What is the probability of selecting a clean number from a 0 28 Jun 2015, 10:20
Display posts from previous: Sort by