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

It is currently 11 Dec 2019, 17:07

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

George's drawer has 10 loose black socks, 15 loose blue socks, and 8

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 59674
George's drawer has 10 loose black socks, 15 loose blue socks, and 8  [#permalink]

Show Tags

New post 22 Jan 2015, 08:09
2
12
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

70% (01:14) correct 30% (01:24) wrong based on 264 sessions

HideShow timer Statistics

George's drawer has 10 loose black socks, 15 loose blue socks, and 8 loose white socks. If George takes socks out of the drawer at random, how many would he need to take out to be sure that the removed socks include at least one matching pair ?

A. 3
B. 4
C. 9
D. 5
E. 31

Kudos for a correct solution.

_________________
Manager
Manager
User avatar
G
Joined: 13 Oct 2013
Posts: 132
Concentration: Strategy, Entrepreneurship
GMAT ToolKit User
Re: George's drawer has 10 loose black socks, 15 loose blue socks, and 8  [#permalink]

Show Tags

New post 22 Jan 2015, 14:44
2
in worst scenario he will draw three different color socks and 4th draw will be a matching pair.
Answer is B
Manager
Manager
avatar
Joined: 14 Jul 2014
Posts: 88
Re: George's drawer has 10 loose black socks, 15 loose blue socks, and 8  [#permalink]

Show Tags

New post 22 Jan 2015, 23:09
1
30 secs

Ans B = 4

600 level ... Really?
Manager
Manager
avatar
Joined: 01 May 2013
Posts: 57
Re: George's drawer has 10 loose black socks, 15 loose blue socks, and 8  [#permalink]

Show Tags

New post 24 Jan 2015, 16:03
2
We plan for the worst case scenario. Let K, B, W = black, blue, white (respectively). Say we draw KBW. No matter what we pick next, we will have a matching pair. The answer is 4 (B).
Current Student
User avatar
B
Joined: 10 Mar 2015
Posts: 50
Schools: Booth '20 (M)
WE: Analyst (Venture Capital)
GMAT ToolKit User
Re: George's drawer has 10 loose black socks, 15 loose blue socks, and 8  [#permalink]

Show Tags

New post 30 Sep 2015, 09:09
1
1
Answer = B

Worst case scenario:
First Pick = Blue
We only have one sock, so no match.
Second Pick = Black
Darn, a different color, still no match.
Third Pick = White
What are the odds, still no match.
Fourth Pick = Black
Hurrah, we now have a pair of black socks!

You can substitute the color of the fourth pick with either blue or white and the answer still hold true, we would have a match.
Manager
Manager
avatar
Joined: 02 Jul 2015
Posts: 101
Schools: ISB '18
GMAT 1: 680 Q49 V33
Re: George's drawer has 10 loose black socks, 15 loose blue socks, and 8  [#permalink]

Show Tags

New post 01 Oct 2015, 08:18
1
Answer is 4

As there are 3 categories, fourth draw will match one of the earlier drawn category.
CEO
CEO
User avatar
D
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2977
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Reviews Badge
Re: George's drawer has 10 loose black socks, 15 loose blue socks, and 8  [#permalink]

Show Tags

New post 03 Oct 2015, 04:00
1
Bunuel wrote:
George's drawer has 10 loose black socks, 15 loose blue socks, and 8 loose white socks. If George takes socks out of the drawer at random, how many would he need to take out to be sure that the removed socks include at least one matching pair ?

A. 3
B. 4
C. 9
D. 5
E. 31

Kudos for a correct solution.


For 1 matching pair the worst scenario is that he picks 3 socks and all 3 are different color

but in that case 4th sock picked has to be a repeated color thereby making a pair

Hence, Minimum socks needed to be picked = 4

Answer: option B

Bunuel: you might want to add an OA in this question as official answer is still not provided.
_________________
Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION
SVP
SVP
User avatar
V
Status: It's near - I can see.
Joined: 13 Apr 2013
Posts: 1702
Location: India
Concentration: International Business, Operations
Schools: INSEAD Jan '19
GPA: 3.01
WE: Engineering (Real Estate)
Reviews Badge CAT Tests
Re: George's drawer has 10 loose black socks, 15 loose blue socks, and 8  [#permalink]

Show Tags

New post 03 Oct 2015, 04:47
2
Bunuel wrote:
George's drawer has 10 loose black socks, 15 loose blue socks, and 8 loose white socks. If George takes socks out of the drawer at random, how many would he need to take out to be sure that the removed socks include at least one matching pair ?

A. 3
B. 4
C. 9
D. 5
E. 31

Kudos for a correct solution.



My Solution:

As we have socks of 3 different colours, in the first three picks we can take out socks of any colour. So to be sure that we have a pair of socks we need to pick forth one. It will pair up with any of the first three socks we chose.

So IMO, answer is 4. Choice B

_________________
"Do not watch clock; Do what it does. KEEP GOING."
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 13742
Re: George's drawer has 10 loose black socks, 15 loose blue socks, and 8  [#permalink]

Show Tags

New post 16 Nov 2019, 16:45
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Club Bot
Re: George's drawer has 10 loose black socks, 15 loose blue socks, and 8   [#permalink] 16 Nov 2019, 16:45
Display posts from previous: Sort by

George's drawer has 10 loose black socks, 15 loose blue socks, and 8

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





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne