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

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

probability

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
Junior | Next Rank: 30 Posts
Posts: 19
Joined: Wed Aug 12, 2009 9:34 pm
Location: india
Thanked: 3 times

by joshi.v123 » Sat Nov 13, 2010 5:29 am
is it 12/28?
Thanks,
VJ
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 131
Joined: Tue Aug 05, 2008 3:28 pm
Thanked: 2 times

by mariah » Sat Nov 13, 2010 6:08 am
13/28 would be the answer if question asked what would b the probability if at least one black - white stem is selected...

but i think that this question asks probability of getting one Black - white and one color set (or vice versa) ...
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 437
Joined: Sat Nov 22, 2008 5:06 amFollowed by: 1 member
Location: India
Thanked: 50 times
GMAT Score:580

by beat_gmat_09 » Sat Nov 13, 2010 6:50 am
mariah wrote:we have six color TV and two black-white TV. If two sets are to be selected at random, what is the probability that one black-white set is selected?



sorry don't have answers and oa
two ways of getting -
BW C or C BW.
prob BW C = 2/8*6/7
prob C BW = 6/8*2/7
req prob - 2/8*6/7 + 6/8*2/7 = 3/7
Hope is the dream of a man awake
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 201
Joined: Sat Jul 10, 2010 2:23 pmFollowed by: 1 member
Thanked: 7 times

by ov25 » Sat Nov 13, 2010 7:25 am
1-30/56 = 26/56 = 13/28

thanks
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 298
Joined: Tue Feb 16, 2010 1:09 amFollowed by: 1 member
Thanked: 2 times

by Deepthi Subbu » Tue Nov 16, 2010 9:12 pm
Am unable to understand , can somebody explain it further?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 905
Joined: Sun Sep 12, 2010 1:38 amFollowed by: 123 members
Thanked: 378 times
GMAT Score:760

by Geva@EconomistGMAT » Wed Nov 17, 2010 2:56 am
Beat_gmat_09 is correct.

Break the problem down to 1st choice, 2nd choice, find the probability of success in each, then multiply.

It seems as if the answer is P(BW on 1st) * P(color on 2nd)) = 2/8 * 6/7 = 1/2 * 3/7 = 3/14

However, that is only one of two possible scenarios of getting "one B/W", the other scenario being P(color on 1st) * P(B/W on 2nd) = 6/8 * 2/7 = 3/4 * 2/7 = 3/2 * 1/7 = 3/14. Not surprising the probability for both scenarios comes down to the same: there really is no reason why the probability of choosing a B/W first should be any different from the probability of choosing a B/W 2nd.

Since the final probability is made of P(choosing B/W on 1st) OR P(choosing B/W on 2nd), the final answer is 3/14+3/14 = 6/14 = 3/7.
Geva
Senior Instructor
Master GMAT
1-888-780-GMAT
https://www.mastergmat.com
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1