BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Combination problem

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 17
Joined: Sat Oct 03, 2009 2:41 pm
by adamz » Thu Oct 27, 2011 7:59 pm
A committee that includes 6 members is about to be divided into 2 subcommittees with 3 members each. On what percent of the possible subcommittees that John is a member of is Roger also a member?

10%
20%
30%
40%
50%

OA:D
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
GMAT Instructor
Posts: 349
Joined: Wed Sep 28, 2011 3:38 pmFollowed by: 54 members
Location: Austin, TX
Thanked: 236 times
GMAT Score:770

by GmatMathPro » Thu Oct 27, 2011 8:16 pm
For any subcommittee that John is in, we can choose the other two members in 5C2=10 ways. For any subcommittee that John AND Roger are on, we can choose the third member in 4 ways.

4/10=40%

D
Pete Ackley
GMAT Math Pro
Free Online Tutoring Trial
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 1035
Joined: Fri Dec 17, 2010 11:13 amFollowed by: 365 members
Location: Los Angeles, CA
Thanked: 474 times

by VivianKerr » Thu Oct 27, 2011 8:17 pm
We need to find out how many of those committees will David + Michael be on together.

Committee #1: There is a 50% chance that David will be a member, leaving 2 options for the other 5 people. Michael's odds are 2/5 or 40%.

Chances of David and Michael being on the first committee toegther will be 50% x 40% = 20%.

Committee #2: Same logic here. Since we don't know which committee they'll be on, we add 20 + 20 = 40.

The answer is D.
Vivian Kerr
GMAT Rockstar, Tutor
https://www.GMATrockstar.com
https://www.yelp.com/biz/gmat-rockstar-los-angeles

Former Kaplan and Grockit instructor, freelance GMAT content creator, now offering affordable, effective, Skype-tutoring for the GMAT at $150/hr. Contact: [email protected]

Thank you for all the "thanks" and "follows"! :-)
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 385
Joined: Fri Sep 23, 2011 9:02 pmFollowed by: 6 members
Thanked: 62 times

by user123321 » Thu Oct 27, 2011 8:31 pm
total no of committees possible = 6c3/2! = 20/2 = 10
committes formed with concerned two members = 4c1

=4/10*100 = 40%

user123321
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Senior | Next Rank: 100 Posts
Posts: 47
Joined: Wed Nov 24, 2010 12:57 am
Thanked: 3 times

by Cheese12 » Fri Oct 28, 2011 3:08 am
total number of possibilities of subcommunities = 6!/3!3! = 20

since Roger and John are fixed...
we see the possiblities fr the rest (2 subcommunites) = 4!/3!1! = 4 x 2 = 8

8/20 * 100 = 40 %
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members
Location: New York, NY
Thanked: 13060 times
GMAT Score:790

by GMATGuruNY » Fri Oct 28, 2011 3:40 am
adamz wrote:A committee that includes 6 members is about to be divided into 2 subcommittees with 3 members each. On what percent of the possible subcommittees that John is a member of is Roger also a member?

10%
20%
30%
40%
50%

OA:D
Question rephrased: What is the probability that Roger is one of the other 2 people selected to be on the committee with John?

P(Roger is NOT selected) = 4/5 * 3/4 = 3/5.
Thus, P(Roger IS selected) = 1 - 3/5 = 2/5 = 40%.

The correct answer is D.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1