Last visit was: 26 Apr 2026, 10:48 It is currently 26 Apr 2026, 10:48
Home
Messages
Tests
Schools
Events
Close
GMAT Club Daily Prep
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
User avatar
asaf
User avatar
Joined: 06 Sep 2006
Last visit: 07 Apr 2008
Posts: 292
Own Kudos:
200
Posts: 292
Kudos: 200
Identify permutation or combination? 1) In how many ways you 06 Oct 2006, 10:00
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Identify permutation or combination?

1) In how many ways you can invite 5 out of 10 friends to a dinner?

2) How many ways can you arrange 10 books on a bookshelf that has space for only 5?

3) A certain state lottery consists of selecting a set of 6 numbers randomly from a set of 49 numbers. To win the lottery, you must select the correct set of six numbers. How many possible lottery tickets are availble?

4) How many ways can 5 people sit on a park bench if the bench can only seat three people?



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.
Where to now? Join ongoing discussions on thousands of quality questions in our Quantitative Questions Forum
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.
Thank you for understanding, and happy exploring!
avatar
Rayn
avatar
Joined: 08 Jul 2006
Last visit: 10 Nov 2006
Posts: 42
Own Kudos:
5
Posts: 42
Kudos: 5
Identify permutation or combination? 1) In how many ways you 06 Oct 2006, 10:04
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Correct me if I'm wrong but I think that they are all combination problems.
avatar
chrismeiyu
avatar
Joined: 26 Jul 2006
Last visit: 20 Jul 2007
Posts: 4
Posts: 4
Kudos: 0
Identify permutation or combination? 1) In how many ways you 06 Oct 2006, 10:18
Kudos
Add Kudos
Bookmarks
Bookmark this Post
yup - when dealing with combination problems, order does NOT matter.
So from the above problems, they are all combination b/c none of them require any kind of order.
avatar
Rayn
avatar
Joined: 08 Jul 2006
Last visit: 10 Nov 2006
Posts: 42
Own Kudos:
5
Posts: 42
Kudos: 5
Identify permutation or combination? 1) In how many ways you 06 Oct 2006, 10:26
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Awesome thanks...
User avatar
jyotsnasarabu
User avatar
Joined: 16 Sep 2006
Last visit: 23 Mar 2007
Posts: 250
Own Kudos:
746
Posts: 250
Kudos: 746
Identify permutation or combination? 1) In how many ways you 06 Oct 2006, 10:40
Kudos
Add Kudos
Bookmarks
Bookmark this Post
This is my take on the given prob's

1). is a combination prob as the order taken is not important and we need to select five to invite them from 10 plp

so the answer according to my approach would be 10c5[c(10,5)]

2). here we use permutation, as the order is important. In an arrangement the order is always taken into consideration.

ans: 10p5

3). This on is definitely a combination problem

C(49,6)*6!*8 is my answer..........why 6!- is coz each set of the lottery has 6 no's associated with it and a total of 8 such sets exist.

4). this again is a permutation problem , since the order of arrangement matters

In short any problem that involves arrangement and order always comes under permutations.

Any problem that asks for selection is invariably a combination prob. here the arrangement does not matter

m not sure if the answers are correct though. It's just an attempt by me.
User avatar
asaf
User avatar
Joined: 06 Sep 2006
Last visit: 07 Apr 2008
Posts: 292
Own Kudos:
200
Posts: 292
Kudos: 200
Identify permutation or combination? 1) In how many ways you 06 Oct 2006, 12:09
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Rayn
Correct me if I'm wrong but I think that they are all combination problems.
Show more


not all of them are combos..
User avatar
londonluddite
User avatar
Joined: 30 Aug 2006
Last visit: 28 Jan 2008
Posts: 221
Own Kudos:
296
Posts: 221
Kudos: 296
Identify permutation or combination? 1) In how many ways you 06 Oct 2006, 12:23
Kudos
Add Kudos
Bookmarks
Bookmark this Post
my take:

1. combo
2. perm
3. combo
4. perm

combo - arrangment does not matter, perm it does



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.
Where to now? Join ongoing discussions on thousands of quality questions in our Quantitative Questions Forum
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!