NEW HERE? LEARN MORE
closeclose
Last visit was: 24 Apr 2024, 23:51 It is currently 24 Apr 2024, 23:51
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

What is the probability that x/y will be an integer where x is a memb

User avatar
rxs0005
Senior Manager
Senior Manager
Joined: 07 Jun 2004
Posts: 438
Own Kudos [?]: 2829 [0]
Given Kudos: 22
Location: PA
Send PM
What is the probability that x/y will be an integer where x is a memb [#permalink] New post   24 Aug 2010, 05:13
00:00
A
B
C
D
E

Difficulty:

55% (hard)

Question Stats:

56% (01:12) correct 44% (01:24) wrong based on 9 sessions
Hide Show timer Statistics
x = {9, 10, 11, 12}

y = {2, 3, 4, 5}

What is the probability that x/y will be an integer where x is a member chosen from set x and y is a member chosen from set y

A. 1/16

B. 3/8

C. 1/2

D. 3/4

E. 15/16


OPEN DISCUSSION OF THIS QUESTION IS HERE: one-number-will-be-chosen-randomly-from-each-of-the-sets-above-if-x-193287.html

Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
ShowHide Answer
Official Answer
B
avatar
iLc
Intern
Intern
Joined: 24 Aug 2010
Posts: 3
Own Kudos [?]: 29 [2]
Given Kudos: 0
Send PM
Re: What is the probability that x/y will be an integer where x is a memb [#permalink] New post   24 Aug 2010, 05:19
2
Kudos
Hello, this is my first contribution to the forum (and english is not my mother language) so pardon me if I don't answer in the right way.

There are 16 possibilities in total (4x and 4y so 4*4 = 16)
The integer are 9/3; 10/2; 10/5; 12/2; 12/3 and 12/4, therefore 6/16 = 3/8

Hope it helps :)
User avatar
soumanag
Manager
Manager
Joined: 09 Jun 2010
Posts: 81
Own Kudos [?]: 356 [0]
Given Kudos: 1
Send PM
Re: What is the probability that x/y will be an integer where x is a memb [#permalink] New post   25 Aug 2010, 09:19
Alternate approach:

Probability of choosing "9" from set 1 & "3" from set 2 = 1/4 X 1/4 = 1/16
probability of choosing "10" from set 1 & 2 or "5" from set 2 = 1/4 X 2/4 = 1/8
probability of choosing "12" from set 1 & "2", "3" or "4" from set 2 = 1/4 X 3/4 = 3/16

Adding all probabilities: 1/16 + 1/8 + 3/16 = 6/16 = 3/8.

This is a lengthier process. I like iLc's approach better :-D
User avatar
gauravnagpal
Manager
Manager
Joined: 23 May 2010
Posts: 164
Own Kudos [?]: 350 [0]
Given Kudos: 112
Send PM
Re: What is the probability that x/y will be an integer where x is a memb [#permalink] New post   25 Aug 2010, 09:52
iLc wrote:
Hello, this is my first contribution to the forum (and english is not my mother language) so pardon me if I don't answer in the right way.

There are 16 possibilities in total (4x and 4y so 4*4 = 16)
The integer are 9/3; 10/2; 10/5; 12/2; 12/3 and 12/4, therefore 6/16 = 3/8

Hope it helps :)


hey welcome to the club ..
what I have realised in the ast 3 months is that somehow language and other things dont matter here..... what matters is a sincere desire to help your fellow clubmember and seek honest help from anybody ....

and plus 1 ( kudos )for the courage to post such a good reply first up ..... u know what was my first question ?
what is GMAT prep ? yes u can laugh at it now ( and so can I )

but there were people who patiently replied to my "most sensible " question !!
again ;
welcome and keep learning , and we will learn from u



.trust me it really doesnot
User avatar
whiplash2411
SVP
SVP
Joined: 09 Jun 2010
Status:Three Down.
Posts: 1764
Own Kudos [?]: 3468 [0]
Given Kudos: 210
Concentration: General Management, Nonprofit
Schools: HBS '17 (M) Stanford '17 (A)
Send PM
GMAT ToolKit User
Re: What is the probability that x/y will be an integer where x is a memb [#permalink] New post   25 Aug 2010, 15:15
rxs0005 wrote:
x= { 9 ,10, 11, 12 }

y = { 2,3,4,5}


what is the probability that x / y will be an integer where x is a member chosen from set x and y is a member chosen from set y


1/16

3/8

1/2

3/4

15/16


Personally I think the simplest way to solve this problem would be to just look at the divisibility of numbers individually since it's so few.

This can be done in two ways. Take each term from set x and see which terms in y they are divisible by or vice versa. I'm taking the first approach.

9: 3
10: 2 and 5
11: -
12: 2, 3 and 4.

So the total combinations that are possible where x/y is an integer is the sum of the above expressed combinations and is equal to 6.

The total number of ways of picking two numbers from the sets would be 4C1*4C1 = 16.

So the required probability is \(\frac{6}{16} = \frac{3}{8}.\)

So answer choice B. Hope this helps.

Quote:
Hello, this is my first contribution to the forum (and english is not my mother language) so pardon me if I don't answer in the right way.


Welcome to GMAT Club iLC. It really doesn't matter if English is your native language or not. As a community, we hope to help and learn from each other and that's what makes this forum extraordinary. Your contributions and questions are always welcome. :)
User avatar
S
aim730
Manager
Manager
Joined: 20 Apr 2010
Posts: 169
Own Kudos [?]: 67 [0]
Given Kudos: 66
Concentration: Tuck,Cornell,Duke
 Q47  V20 GMAT 2: 560  Q45  V22
WE 1: 4.6 years Exp IT prof
Send PM
Reviews Badge
Re: What is the probability that x/y will be an integer where x is a memb [#permalink] New post   25 Aug 2010, 17:06
Answer is definitely 6/16= 3/8. Hence B

Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
gmatclubot
Re: What is the probability that x/y will be an integer where x is a memb [#permalink]
25 Aug 2010, 17:06
Moderators:
Bunuel
Math Expert
92900 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions