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

 It is currently 22 Feb 2019, 13:27

### 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 February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
• ### 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
• ### 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.

# 10 members of a society, including members A and B, attended a me

Author Message
TAGS:

### Hide Tags

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6985
GMAT 1: 760 Q51 V42
GPA: 3.82
10 members of a society, including members A and B, attended a me  [#permalink]

### Show Tags

06 Mar 2018, 02:58
00:00

Difficulty:

15% (low)

Question Stats:

79% (01:20) correct 21% (01:40) wrong based on 92 sessions

### HideShow timer Statistics

[GMAT math practice question]

10 members of a society, including members A and B, attended a meeting. 2 of these members were selected to form a committee. What is the probability that the 2 members selected were members A and B?

A. 1/10
B. 1/15
C. 1/20
D. 1/30
E. 1/45

_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $149 for 3 month Online Course" "Free Resources-30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons - try it yourself" CEO Joined: 11 Sep 2015 Posts: 3447 Location: Canada Re: 10 members of a society, including members A and B, attended a me [#permalink] ### Show Tags 06 Mar 2018, 07:06 Top Contributor MathRevolution wrote: [GMAT math practice question] 10 members of a society, including members A and B, attended a meeting. 2 of these members were selected to form a committee. What is the probability that the 2 members selected were members A and B? A. 1/10 B. 1/15 C. 1/20 D. 1/30 E. 1/45 Let's apply some probability rules P(A and B both selected) = P(1st selection is one member of the pair AND 2nd selection is the other member of the pair) = P(1st selection is one one member of the pair) x P(2nd selection is the other member of the pair) = 2/10 x 1/9 = 1/45 Answer: E RELATED VIDEO FROM OUR COURSE _________________ Test confidently with gmatprepnow.com CEO Status: GMATINSIGHT Tutor Joined: 08 Jul 2010 Posts: 2799 Location: India GMAT: INSIGHT Schools: Darden '21 WE: Education (Education) Re: 10 members of a society, including members A and B, attended a me [#permalink] ### Show Tags 06 Mar 2018, 07:18 MathRevolution wrote: [GMAT math practice question] 10 members of a society, including members A and B, attended a meeting. 2 of these members were selected to form a committee. What is the probability that the 2 members selected were members A and B? A. 1/10 B. 1/15 C. 1/20 D. 1/30 E. 1/45 Favourable ways of choosing committee = 1 (A and B both) Total ways of selecting a 2 member committee out of 10 members = 10C2 = 45 Probability = 1/45 answer: Option E _________________ 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 Math Revolution GMAT Instructor Joined: 16 Aug 2015 Posts: 6985 GMAT 1: 760 Q51 V42 GPA: 3.82 Re: 10 members of a society, including members A and B, attended a me [#permalink] ### Show Tags 08 Mar 2018, 01:25 => The number of committees of 2 people that include members A and B is equal to the number of ways that 2 people can be selected from 2 people, which is 2C2 = 1. The number different possible committees of 2 people, is equal to the number of ways that 2 people can be selected from 10 people, which is 10C2 = $$\frac{(10*9)}{(1*2)} = 45.$$ The probability that the committee contains members A and B is 2C2 / 10C2 = $$\frac{1}{45}$$. Therefore, the answer is E. Answer: E _________________ MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only$149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Manager
Joined: 28 Jan 2018
Posts: 52
Location: Netherlands
Concentration: Finance
GMAT 1: 710 Q50 V36
GPA: 3
Re: 10 members of a society, including members A and B, attended a me  [#permalink]

### Show Tags

20 Mar 2018, 16:23
MathRevolution wrote:
[GMAT math practice question]

10 members of a society, including members A and B, attended a meeting. 2 of these members were selected to form a committee. What is the probability that the 2 members selected were members A and B?

A. 1/10
B. 1/15
C. 1/20
D. 1/30
E. 1/45

Probability of choosing both A and B = $$\frac{2}{10} * \frac{1}{9} = \frac{1}{45}$$

The first part of the equation is $$\frac{2}{10}$$ because it can be either A or B, while the 2nd is $$\frac{1}{9}$$ because it's the only remaining member
Re: 10 members of a society, including members A and B, attended a me   [#permalink] 20 Mar 2018, 16:23
Display posts from previous: Sort by