GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 23 Feb 2019, 07:09

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.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
  • FREE Quant Workshop by e-GMAT!

     February 24, 2019

     February 24, 2019

     07:00 AM PST

     09:00 AM PST

    Get personalized insights on how to achieve your Target Quant Score.
  • Free GMAT RC Webinar

     February 23, 2019

     February 23, 2019

     07:00 AM PST

     09:00 AM PST

    Learn reading strategies that can help even non-voracious reader to master GMAT RC. Saturday, February 23rd at 7 AM PT

A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

 
Director
Director
avatar
Joined: 07 Jun 2004
Posts: 589
Location: PA
A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another  [#permalink]

Show Tags

New post 27 Sep 2010, 14:25
4
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

45% (01:37) correct 55% (01:29) wrong based on 91 sessions

HideShow timer Statistics

A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another bag has 60 marbles numbered consecutively 90 - 149 inclusive. If a marble is randomly chosen from each bag, what is the probability that two marbles have the same number

1/10

1/60

1/100

1/600

1/6000
CEO
CEO
User avatar
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2576
Location: Malaysia
Concentration: Technology, Entrepreneurship
Schools: ISB '15 (M)
GMAT 1: 670 Q49 V31
GMAT 2: 710 Q50 V35
Reviews Badge
Re: A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another  [#permalink]

Show Tags

New post 27 Sep 2010, 14:44
rxs0005 wrote:
A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another bag has 60 marbles numbered consecutively 90 - 149 inclusive. If a marble is randomly chosen from each bag, what is the probability that two marbles have the same number


1/10

1/60

1/100

1/600

1/6000


Common numbers : 90,91...99 total 10 numbers

probability = \(\frac{10}{{100*60}}\) = \(\frac{1}{{600}}\) = D
_________________

Fight for your dreams :For all those who fear from Verbal- lets give it a fight

Money Saved is the Money Earned :)

Jo Bole So Nihaal , Sat Shri Akaal

:thanks Support GMAT Club by putting a GMAT Club badge on your blog/Facebook :thanks

GMAT Club Premium Membership - big benefits and savings

Gmat test review :
http://gmatclub.com/forum/670-to-710-a-long-journey-without-destination-still-happy-141642.html

Retired Moderator
User avatar
Joined: 02 Sep 2010
Posts: 762
Location: London
GMAT ToolKit User Reviews Badge
Re: A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another  [#permalink]

Show Tags

New post 27 Sep 2010, 14:47
No of ways to pick two marbles = 100*60 = 6000

No of ways to pick same number = (90,90) , ... , (99,99) = 10

So probability = 1/600
_________________

Math write-ups
1) Algebra-101 2) Sequences 3) Set combinatorics 4) 3-D geometry

My GMAT story

GMAT Club Premium Membership - big benefits and savings

Senior Manager
Senior Manager
User avatar
Status: Time to step up the tempo
Joined: 24 Jun 2010
Posts: 354
Location: Milky way
Schools: ISB, Tepper - CMU, Chicago Booth, LSB
Re: A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another  [#permalink]

Show Tags

New post 27 Sep 2010, 19:50
1
rxs0005 wrote:
A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another bag has 60 marbles numbered consecutively 90 - 149 inclusive. If a marble is randomly chosen from each bag, what is the probability that two marbles have the same number


1/10

1/60

1/100

1/600

1/6000


My approach:

Pickup the matching 10 numbered marbles from the first bag -- Probability - 10/100 -- 1/10

Now we have one of the marble numbered from 90 - 99. From the other bag we need to pick just the one marble which will have a number from 90 - 99 to ensure we have a matching marble set. Its probability is 1/60.

Hence combined probability is (1/10) * (1/60) -- 1/600. Answer D.

There is a similar question in this forum , check this out -- http://gmatclub.com/forum/junior-58914.html
_________________

:good Support GMAT Club by putting a GMAT Club badge on your blog :thanks

Manager
Manager
User avatar
Joined: 16 Sep 2010
Posts: 119
Location: India
Schools: Terry, Georgia Tech
WE 1: Working for Wipro Technologies since April 2010
Re: A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another  [#permalink]

Show Tags

New post 27 Sep 2010, 21:03
ezhilkumarank wrote:
rxs0005 wrote:
A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another bag has 60 marbles numbered consecutively 90 - 149 inclusive. If a marble is randomly chosen from each bag, what is the probability that two marbles have the same number


1/10

1/60

1/100

1/600

1/6000


My approach:

Pickup the matching 10 numbered marbles from the first bag -- Probability - 10/100 -- 1/10

Now we have one of the marble numbered from 90 - 99. From the other bag we need to pick just the one marble which will have a number from 90 - 99 to ensure we have a matching marble set. Its probability is 1/60.

Hence combined probability is (1/10) * (1/60) -- 1/600. Answer D.

There is a similar question in this forum , check this out -- http://gmatclub.com/forum/junior-58914.html


my approach.....

probability of picking a marble from 0 -99 in the first set = 1/100 { since 0-99 is hundred marbles}

similarly, probability of picking a marble from 90-149 in the second set = 1/60

therefore, probability that they are same = (1/100) * (1/60) = 1/6000

it can happen for 10 marbles ( 90 to 99 inclusive ) .

Thus, total probability = 10 *1/6000 = 1/600 ANS
_________________

Samidh
-------------------------------------------------------------------------------------------
Feel free to get in touch if you feel I can be of some assistance to you. You can find me in Facebook if you search!


Consider giving me some kudos if you like my post

Manager
Manager
User avatar
B
Status: Gathering chakra
Joined: 05 Feb 2018
Posts: 65
A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another  [#permalink]

Show Tags

New post 24 Jan 2019, 14:52
Official answer:
Take the first bag of 100 marbles. 10 of the numbers overlap, so there is a 10/100 chance that there is a possibility of an overlap. (There’s a 90% chance already that the numbers will not be the same; for instance, that’s the case if the first marble drawn is numbered 72.) Once the first marble is drawn, the only way the two marbles will have the same number is if the second marble has exactly the same number. In other words, if we drew 96 from the first bag, we’re looking for the probability of drawing 96 from the second bag, as well. The probability of drawing a specific number from the second bag is 1/60. In order to draw the same marble from both bags, we need both of those events to happen, so we multiply the probabilities:
1/10 × 1/60 = 1/600, choice (D).
GMAT Club Bot
A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another   [#permalink] 24 Jan 2019, 14:52
Display posts from previous: Sort by

A bag has 100 marbles numbered consecutively 0 - 99 inclusive. Another

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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®.