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 Your Progress
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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
Are you attending an MBA or Masters program outside in the US or Europe and wondering how to finance your studies? In this exclusive conversation, we discuss the collateral-free non-cosigner education loans...
Solve 30 high quality GMAT Focus practice questions in timed conditions. Take this GMAT practise test live with peers, analyze your GMAT study progress, and see where you stand in the GMAT student pool.
Join us in a comprehensive talk about the F1 Student Visa process with Travis Feuerbacher, former U.S. Visa Officer and licensed U.S. immigration attorney having expertise working for the U.S. Department of State
Ready to skyrocket your career with an MBA? Get ahead with our curated list of FREE courses and resources to kickstart your journey into business education!
For more than a decade, Target Test Prep has been helping GMAT students clear seemingly impossible hurdles and achieve MASSIVE score increases on test day. Our students prove time and time again that there is no “ceiling”...
Do RC/MSR passages scare you? e-GMAT is conducting a masterclass to help you learn – Learn effective reading strategies, Tackle difficult RC & MSR with confidence, and Excel in timed test environment
Join us for an exclusive one-day event focused on mastering the GMAT and maximizing your preparation resources! Here's what you can expect: Don't miss out on this invaluable opportunity to supercharge your GMAT preparation journey.
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Re: Combinatorics: balls put into boxes
[#permalink]
09 Jan 2014, 21:43
1
Kudos
Expert Reply
Meitene007 wrote:
In how many ways can 4 (distinguishable) balls be put into 5 (distinguishable) boxes so that exactly 3 boxes are not empty?
Please provide detailed explanation.
Please note that you must provide options in PS questions.
4 distinct balls 5 distinct boxes - 2 must be empty
First choose the 2 boxes which will be empty in 5C2 ways. Now you have 4 distinct balls and 3 distinct boxes. Since no box should be empty, the only distribution which will work is 2, 1, 1 i.e. 2 balls in one box and 1 each in other two boxes. Choose the box which will have 2 balls in 3C1 ways. Choose the two balls that will go together in the box in 4C2 ways. The other two balls will be distributed to the other two boxes in 2! ways.
Total ways = 5C2 * 3C1 * 4C2 * 2! = 360 ways
Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
_________________
Karishma Bansal - ANA PREP
*SUPER SUNDAYS!* - FREE Access to ALL Resources EVERY Sunday REGISTER at ANA PREP (Includes access to Study Modules, Concept Videos, Practice Questions and LIVE Classes)
Re: Combinatorics: balls put into boxes
[#permalink]
09 Jan 2014, 17:40
In how many ways can 7 (distinguishable) balls be put into 12 boxes (2 boxes are equaly green (indistinguishable) and 10 are equaly yellow (indistinguishable)?
Please provide steps how to get to the correct answer.
gmatclubot
Re: Combinatorics: balls put into boxes [#permalink]