Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
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.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
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 Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart 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 563 reviewsTarget Test Prep

Help on solving a combination problem

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Legendary Member
Posts: 882
Joined: Fri Feb 20, 2009 2:57 pmFollowed by: 1 member
Thanked: 15 times
GMAT Score:690
by crackgmat007 » Mon Apr 13, 2009 8:39 pm
Since only Tom or Jerry can be on the committe, I considered Tom & Jerry as 'one' for calucating the combinations. Hence, 6C3 = 20.

Answer seems to be C (30)...am I missing something?
You do not have the required permissions to view the files attached to this post.
Top
Join the discussion
Source: — Problem Solving |
Junior | Next Rank: 30 Posts
Posts: 21
Joined: Fri Mar 13, 2009 9:35 pm
Thanked: 1 times

by kirvar » Mon Apr 13, 2009 9:06 pm
Number of groups with only Tom: 5C2 = 10

Number of groups with only Jerry: 5C2 = 10

Number of groups with neither Jerry nor Tom: 5C3 =10

Total = 30
Top
Join the discussion
Legendary Member
Posts: 2467
Joined: Thu Aug 28, 2008 6:14 pmFollowed by: 11 members
Thanked: 331 times

by cramya » Mon Apr 13, 2009 9:09 pm
Tom and Jerry are 2 different persons.

One way to do it is to first find the total number of 3 member sub committes possible from 7 people

7C3 = 35

Then find the number of subcomitees in which Tom and Jerry will be there.

2c2( which iequals 1) * 5c1 (once u choose Tom and Jerry u have 5 persons remaining to choose 1 from) = 5


Subtract 2 from 1 which will give u the number of 3 member commitees where Tom and Jerry will not be there

35 - 5

= 30

Regards,
CR
Top
Join the discussion