Last visit was: 24 Apr 2026, 00:56 It is currently 24 Apr 2026, 00:56
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.
Close
Request Expert Reply
Confirm Cancel
User avatar
japped187
Joined: 21 Mar 2007
Last visit: 02 Jun 2008
Posts: 52
Own Kudos:
686
 [52]
Posts: 52
Kudos: 686
 [52]
5
Kudos
Add Kudos
47
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 23 Apr 2026
Posts: 109,802
Own Kudos:
Given Kudos: 105,868
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,802
Kudos: 810,909
 [12]
7
Kudos
Add Kudos
5
Bookmarks
Bookmark this Post
General Discussion
avatar
jimmylow
Joined: 31 Oct 2007
Last visit: 28 Aug 2014
Posts: 56
Own Kudos:
136
 [3]
Location: Frankfurt, Germany
Posts: 56
Kudos: 136
 [3]
2
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
GMATinsight
User avatar
Major Poster
Joined: 08 Jul 2010
Last visit: 23 Apr 2026
Posts: 6,976
Own Kudos:
16,909
 [2]
Given Kudos: 128
Status:GMAT/GRE Tutor l Admission Consultant l On-Demand Course creator
Location: India
GMAT: QUANT+DI EXPERT
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
WE:Education (Education)
Products:
Expert
Expert reply
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
Posts: 6,976
Kudos: 16,909
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
japped187
A certain company has 18 equally qualified applicants for 4 open positions. How many different groups of 4 applicants can be chosen by the company to fill the positions if the order of selection does not matter?

(A) 18
(B) 72
(C) 180
(D) 1,260
(E) 3,060

Initially There are 18 choices for first Position
Now, There are 17 choices for Second Position
Now, There are 16 choices for Third Position
Now, There are 15 choices for Forth Position

i.e. Total Ways to choose people (With arrangement) = 18*17*16*15

Since we require only the selection hence we need to exclude the arrangements of 4 selected individuals which is 4!


i.e. i.e. Total Ways to choose people (WithOUT arrangement) = (18*17*16*15)/4! = 3060

Answer: Option E
User avatar
GMATDemiGod
Joined: 23 Sep 2015
Last visit: 05 Feb 2017
Posts: 64
Own Kudos:
Given Kudos: 213
Concentration: General Management, Finance
GMAT 1: 680 Q46 V38
GMAT 2: 690 Q47 V38
GPA: 3.5
GMAT 2: 690 Q47 V38
Posts: 64
Kudos: 52
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
jpr200012
A certain company has 18 equally qualified applicants for 4 open positions. How many different groups of 4 applicants can be chosen by the company to fill the positions if the order of selection does not matter?

(A) 18
(B) 72
(C) 180
(D) 1,260
(E) 3,060

# of ways to choose 4 different people out of 18, when order of chosen people doesn't matter is \(C^4_{18}=\frac{18!}{14!*4!}=3060\).

Answer: E.
if order mattered how would this problem change?
User avatar
ENGRTOMBA2018
Joined: 20 Mar 2014
Last visit: 01 Dec 2021
Posts: 2,319
Own Kudos:
3,890
 [1]
Given Kudos: 816
Concentration: Finance, Strategy
GMAT 1: 750 Q49 V44
GPA: 3.7
WE:Engineering (Aerospace and Defense)
Products:
GMAT 1: 750 Q49 V44
Posts: 2,319
Kudos: 3,890
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
GMATDemiGod
Bunuel
jpr200012
A certain company has 18 equally qualified applicants for 4 open positions. How many different groups of 4 applicants can be chosen by the company to fill the positions if the order of selection does not matter?

(A) 18
(B) 72
(C) 180
(D) 1,260
(E) 3,060

# of ways to choose 4 different people out of 18, when order of chosen people doesn't matter is \(C^4_{18}=\frac{18!}{14!*4!}=3060\).

Answer: E.
if order mattered how would this problem change?
If the order mattered, then the 4 people you selected out of 18 via 18C4 need to be multiplied by 4 to account for the fact that 4 positions will themselves be arranged in 4! ways.

Thus total ways possible with an ordered set = 18C4* 4!
User avatar
DJ1986
Joined: 05 Jul 2015
Last visit: 16 May 2016
Posts: 51
Own Kudos:
232
 [1]
Given Kudos: 3
Concentration: Real Estate, International Business
GMAT 1: 600 Q33 V40
GPA: 3.3
GMAT 1: 600 Q33 V40
Posts: 51
Kudos: 232
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
18 * 17 * 16 * 15
Is a little bigger than 20*15*15*15

Divide away 4*3*2

5*5*15*15/2

Little more than close to 3,000

Answer E

Tip: Multiplying by 15 is quick and easy. Add a 0 (*10) and then add half of the number
avatar
SeregaP
Joined: 03 Jan 2017
Last visit: 10 Feb 2018
Posts: 80
Own Kudos:
91
 [1]
Given Kudos: 4
Posts: 80
Kudos: 91
 [1]
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
this is an easy combinatorics question

Combination formula will make it: 4C18=3060
User avatar
JeffTargetTestPrep
User avatar
Target Test Prep Representative
Joined: 04 Mar 2011
Last visit: 05 Jan 2024
Posts: 2,974
Own Kudos:
Given Kudos: 1,646
Status:Head GMAT Instructor
Affiliations: Target Test Prep
Expert
Expert reply
Posts: 2,974
Kudos: 8,710
Kudos
Add Kudos
Bookmarks
Bookmark this Post
japped187
A certain company has 18 equally qualified applicants for 4 open positions. How many different groups of 4 applicants can be chosen by the company to fill the positions if the order of selection does not matter?

(A) 18
(B) 72
(C) 180
(D) 1,260
(E) 3,060

Since order does not matter, 4 people can be chosen from 18 in:

18C4 = 18!/(4! x 14!) = (18 x 17 x 16 x 15)/4! = (18 x 17 x 16 x 15)/(4 x 3 x 2) = 3 x 17 x 4 x 15 = 3,060 ways.

Answer: E
User avatar
EMPOWERgmatRichC
User avatar
Major Poster
Joined: 19 Dec 2014
Last visit: 31 Dec 2023
Posts: 21,777
Own Kudos:
Given Kudos: 450
Status:GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Expert
Expert reply
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Posts: 21,777
Kudos: 13,047
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi All,

We're told that a certain company has 18 equally qualified applicants for 4 open positions. We're asked for the number of different groups of 4 applicants that can be chosen by the company to fill the positions if the order of selection does not matter. This question is a fairly straight-forward Combination Formula question (as a number of the other posts in this thread have shown). Once you recognize that that formula can be applied, you can actually avoid doing some of that math though:

The numerator of that Combination Formula calculation will include the number 17. Since that number is a prime number, there's nothing in the denominator that can 'reduce it' - meaning that the correct answer MUST be a multiple of 17. As such, you can quickly eliminate the first 3 answers (since they are clearly NOT multiples of 17). With a little work, you can also eliminate Answer D (since it's not a multiple of 17 either). That just leaves the correct answer...

Final Answer:

GMAT assassins aren't born, they're made,
Rich
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,965
Own Kudos:
Posts: 38,965
Kudos: 1,117
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Math Expert
109802 posts
Tuck School Moderator
853 posts