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.

Lets play marbels

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Senior | Next Rank: 100 Posts
Posts: 53
Joined: Sat Oct 29, 2011 3:49 amFollowed by: 1 member
Thanked: 2 times
by gmat6087 » Wed Oct 24, 2012 4:44 am
5. There are 7 red and 5 blue marbles in a jar. In how many ways 8 marbles can be selected from the jar so that at least one red marble and at least one blue marble to remain in the jar?
A. 460
B. 490
C. 493
D. 455
E. 445

OAD

My question is can we solve it as given below

7c4*5c4 + 7c5*5c3 + 7c6*5c2

Please respond
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
Master | Next Rank: 500 Posts
Posts: 279
Joined: Mon Jun 25, 2012 10:56 pmFollowed by: 10 members
Thanked: 60 times

by anuprajan5 » Wed Oct 24, 2012 5:57 am
Hi,

Your method is a bit lengthy. How I attacked this was to turn this around.

I figured out total combinations - 12C8 = 495

The combinations where there was no red marble or no blue marble

7C7*5C1+5C5*7C3 = 40

[spoiler]Answer is 495-40 = 455. Hence D[/spoiler]
Regards
Anup

The only lines that matter - are the ones you make!

https://www.youtube.com/watch?v=kk4sZcG ... ata_player
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Senior | Next Rank: 100 Posts
Posts: 80
Joined: Sat Sep 15, 2012 1:07 amFollowed by: 1 member
Thanked: 1 times

by AIM TO CRACK GMAT » Wed Oct 24, 2012 6:09 am
anuprajan5 wrote:Hi,

Your method is a bit lengthy. How I attacked this was to turn this around.

I figured out total combinations - 12C8 ??= 495

The combinations where there was no red marble or no blue marble

7C7*5C1+5C5*7C3 = 40 ?????????

[spoiler]Answer is 495-40 = 455. Hence D[/spoiler]

Anup... its a very nice method... however.. ill b glad if u cud jus xpand certain thins as m a bit slow at undastandin...
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 279
Joined: Mon Jun 25, 2012 10:56 pmFollowed by: 10 members
Thanked: 60 times

by anuprajan5 » Wed Oct 24, 2012 6:19 am
I apologize.

7C7*5C1+5C5*7C3 = 40

All red selected* remaining blue or All blue selectd*remaining red. Basically what I am trying to do is remove the combinations where all the red or all the blue are selected such that the jar contains 0 blue or 0 red.

Since the condition is that it needs atleast 1 blue and 1 red, if you remove these combinations, all other combinations will have atleast 1 red and 1 blue marble in the jar.

I hope that helps.
Regards
Anup

The only lines that matter - are the ones you make!

https://www.youtube.com/watch?v=kk4sZcG ... ata_player
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1