GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 20 Nov 2018, 05:45

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

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

Events & Promotions

Events & Promotions in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
• All GMAT Club Tests are Free and open on November 22nd in celebration of Thanksgiving Day!

November 22, 2018

November 22, 2018

10:00 PM PST

11:00 PM PST

Mark your calendars - All GMAT Club Tests are free and open November 22nd to celebrate Thanksgiving Day! Access will be available from 0:01 AM to 11:59 PM, Pacific Time (USA)
• Free lesson on number properties

November 23, 2018

November 23, 2018

10:00 PM PST

11:00 PM PST

Practice the one most important Quant section - Integer properties, and rapidly improve your skills.

why is the following question a permutation and not a combination

Author Message
TAGS:

Hide Tags

Manager
Joined: 29 May 2017
Posts: 107
Location: Pakistan
Concentration: Social Entrepreneurship, Sustainability
why is the following question a permutation and not a combination  [#permalink]

Show Tags

13 Jul 2018, 04:28
In a group of 10 people, 3 prizes od $20,$10, and $5 are to be given. How many ways can the prizes be distributed? answer is 720 the yt video says that orders matters in this....but how and why? MBA Section Director Affiliations: GMATClub Joined: 22 May 2017 Posts: 1011 Concentration: Nonprofit GPA: 4 WE: Engineering (Computer Software) why is the following question a permutation and not a combination [#permalink] Show Tags 13 Jul 2018, 06:59 1 Lets think of the above question like this. In a group of 10 people, 3 prizes of$20, $10, and$5 are to be given.

Lets assume there is another prize(Loser) that is given to all the other people who are not first, second or third.

Now the question becomes, in how many ways the four prizes can be given to 10 people

=> We need to pick 3 people for first three prizes and the remaining seven people we don't need to pick. Once we pick 1, 2 and 3 the remaining 7 will automatically gets the Loser prize.

Total number of ways to pick 10 people = $$10!$$

Since the above number also includes different ways of picking the remaining 7 people and we actually don't need to pick remaining 7, we divide 10! by 7!

=> $$\frac{10!}{7!}$$ = 720

_________________
MBA Section Director
Affiliations: GMATClub
Joined: 22 May 2017
Posts: 1011
Concentration: Nonprofit
GPA: 4
WE: Engineering (Computer Software)
Re: why is the following question a permutation and not a combination  [#permalink]

Show Tags

13 Jul 2018, 07:48
Also check this thread https://gmatclub.com/forum/permutations ... 10838.html

It has different types of permutation and combination problems to practice on.
_________________
Re: why is the following question a permutation and not a combination &nbs [#permalink] 13 Jul 2018, 07:48
Display posts from previous: Sort by