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.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

A drawer has six loose blue socks and six loose white socks. [#permalink]
23 Sep 2012, 07:06

1

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

85% (hard)

Question Stats:

51% (02:58) correct
49% (01:46) wrong based on 83 sessions

A drawer has six loose blue socks and six loose white socks. If four socks are removed from the drawer at random and without replacement. What is the probability that one pair of each color was selected?

Re: A drawer has six loose blue socks and six loose white socks. [#permalink]
23 Sep 2012, 07:59

1

This post received KUDOS

Expert's post

solo1234 wrote:

A drawer has six loose blue socks and six loose white socks. If four socks are removed from the drawer at random and without replacement. What is the probability that one pair of each color was selected?

A. 2/33 B. 5/66 C. 5/33 D. 5/11 E. 1/2

So, we want the probability of removing 2 blues socks out of 6 and 2 white socks out of 6, while removing 4 socks out of 12.

Re: A drawer has six loose blue socks and six loose white socks. [#permalink]
23 Sep 2012, 18:05

Bunuel wrote:

solo1234 wrote:

A drawer has six loose blue socks and six loose white socks. If four socks are removed from the drawer at random and without replacement. What is the probability that one pair of each color was selected?

A. 2/33 B. 5/66 C. 5/33 D. 5/11 E. 1/2

So, we want the probability of removing 2 blues socks out of 6 and 2 white socks out of 6, while removing 4 socks out of 12.

Re: A drawer has six loose blue socks and six loose white socks. [#permalink]
24 Sep 2012, 23:27

No of Loose blue socks = 6 (3 pairs) No. of Loose white Socks = 6 (3 pairs) total no. of blue and white socks = 12 Total no. of socks to be selected = 4

So we have C (12,4) = no of ways the socks can be selected = 495

No of ways One pair of blue socks is selected ( 2 blue socks) , C (6,2) , No of ways one pair of white socks can be selected C (6,2) ..Because we have to find a scenario where EXACTLY one pair of Blue socks and ONE pair of WHITE socks is selected we will multiply the two .. ie 15 x 15 ..

Filling the information in the Probability formula we get P (A) = (15 x 15) / 495 = 5 : 11 (D) _________________

"When you want to succeed as bad as you want to breathe, then you’ll be successful.” - Eric Thomas

Re: A drawer has six loose blue socks and six loose white socks. [#permalink]
26 May 2013, 08:43

Bunuel wrote:

solo1234 wrote:

A drawer has six loose blue socks and six loose white socks. If four socks are removed from the drawer at random and without replacement. What is the probability that one pair of each color was selected?

A. 2/33 B. 5/66 C. 5/33 D. 5/11 E. 1/2

So, we want the probability of removing 2 blues socks out of 6 and 2 white socks out of 6, while removing 4 socks out of 12.

Re: A drawer has six loose blue socks and six loose white socks. [#permalink]
26 May 2013, 23:48

Expert's post

apd2006 wrote:

Bunuel wrote:

solo1234 wrote:

A drawer has six loose blue socks and six loose white socks. If four socks are removed from the drawer at random and without replacement. What is the probability that one pair of each color was selected?

A. 2/33 B. 5/66 C. 5/33 D. 5/11 E. 1/2

So, we want the probability of removing 2 blues socks out of 6 and 2 white socks out of 6, while removing 4 socks out of 12.

Re: A drawer has six loose blue socks and six loose white socks. [#permalink]
27 May 2013, 02:08

But our answers differ. Which approach/answer is correct? In your approach to solution ,you are replacing (taking number of different combinations of 4 at a time, that means you are replacing the socks back, otherwise why is the count of socks not decreasing? and this is done in both -while calculating the favorable and total outcomes.)

Re: A drawer has six loose blue socks and six loose white socks. [#permalink]
27 May 2013, 02:59

Expert's post

apd2006 wrote:

But our answers differ. Which approach/answer is correct? In your approach to solution ,you are replacing (taking number of different combinations of 4 at a time, that means you are replacing the socks back, otherwise why is the count of socks not decreasing? and this is done in both -while calculating the favorable and total outcomes.)