Last visit was: 14 Jul 2025, 05:20 It is currently 14 Jul 2025, 05:20
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
PrepTap
Joined: 22 Apr 2015
Last visit: 13 Sep 2017
Posts: 60
Own Kudos:
469
 [14]
Given Kudos: 6
Posts: 60
Kudos: 469
 [14]
Kudos
Add Kudos
14
Bookmarks
Bookmark this Post
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 13 Jul 2025
Posts: 102,569
Own Kudos:
741,241
 [1]
Given Kudos: 98,178
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,569
Kudos: 741,241
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
EMPOWERgmatRichC
User avatar
Major Poster
Joined: 19 Dec 2014
Last visit: 31 Dec 2023
Posts: 21,788
Own Kudos:
12,490
 [1]
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: 21,788
Kudos: 12,490
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
fahdman
Joined: 23 Nov 2023
Last visit: 07 Mar 2024
Posts: 14
Own Kudos:
Given Kudos: 55
Posts: 14
Kudos: 1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
­Hello Bunuel,

I hope you are doing great.

Please, I wanted to solve it through this method but I don't know why it does not work.

I started by saying that the guest list will have 4 options since it cannot be the last one (because we need to send invites after)

So:

1) guest list will have 4 options
2) then the invites need to be right after it so I guess it will have one option ?
3) the 3rd event will have 3 remaining option
4) the fourth will have 2 
5) and the last will have 1

4*1*3*2*1 is 24 . where did I missed it ? please, help me solve it through this reasoning. Have a good day­
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 13 Jul 2025
Posts: 102,569
Own Kudos:
741,241
 [3]
Given Kudos: 98,178
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,569
Kudos: 741,241
 [3]
3
Kudos
Add Kudos
Bookmarks
Bookmark this Post
fahdman
Joey is planning to throw a small party and for that he needs to do the following tasks:
I. Decide guest list
II. Send invites
III. Arrange catering
IV. Decide the venue
V. Rent a music system
The tasks can be done in any order as long as the invites are sent after the guest list is decided. In how many ways can Joey do the five tasks listed above?

  • A. 24
    B. 48
    C. 60
    D. 120
    E. 240
  •  

­Hello Bunuel,

I hope you are doing great.

Please, I wanted to solve it through this method but I don't know why it does not work.

I started by saying that the guest list will have 4 options since it cannot be the last one (because we need to send invites after)

So:

1) guest list will have 4 options
2) then the invites need to be right after it so I guess it will have one option ?
3) the 3rd event will have 3 remaining option
4) the fourth will have 2 
5) and the last will have 1

4*1*3*2*1 is 24 . where did I missed it ? please, help me solve it through this reasoning. Have a good day­
­
The issue is that the invites being sent after deciding the guest list doesn't mean they must be sent right afterwards. They just need to follow, not be next. That's a key misunderstanding. I'd still advise studying the solutions presented above and following the links to similar questions to better understand the concept.
User avatar
samriddhi1234
Joined: 19 Aug 2022
Last visit: 14 Jul 2025
Posts: 39
Own Kudos:
Given Kudos: 200
Products:
Posts: 39
Kudos: 20
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi Bunuel

Please let me know if my reasoning is valid or if I'm going wrong anywhere, because I'm getting the correct answer.

As there are 5 tasks, we can arrange them in 5 x 1 (assuming 1st one is guest list so this task needs to be send invites) x 3 x 2 x 1 = 30 ways. and then the first two tasks can be arranged in 2! ways, so 30 x 2 = 60 ways. Is this also correct?

Appreciate the help!


Bunuel
PrepTap
Joey is planning to throw a small party and for that he needs to do the following tasks:
I. Decide guest list
II. Send invites
III. Arrange catering
IV. Decide the venue
V. Rent a music system
The tasks can be done in any order as long as the invites are sent after the guest list is decided. In how many ways can Joey do the five tasks listed above?


A. 24
B. 48
C. 60
D. 120
E. 240

These 5 tasks can be arranged in 5! = 120 ways. In half of them invites are sent after the guest list is decided and in half of them before. So, there are total of 120/2 = 60 ways to arrange the task so that the invites are sent after the guest list is decided.

Answer: C.

Questions about the same concept to practice:
https://gmatclub.com/forum/susan-john-d ... 30743.html
https://gmatclub.com/forum/meg-and-bob- ... 58095.html
https://gmatclub.com/forum/in-how-many- ... 91460.html
https://gmatclub.com/forum/mary-and-joe ... 26407.html
https://gmatclub.com/forum/goldenrod-an ... 82214.html
https://gmatclub.com/forum/six-mobsters ... 26151.html

Hope it helps.
User avatar
Krunaal
User avatar
PS Forum Moderator
Joined: 15 Feb 2021
Last visit: 14 Jul 2025
Posts: 691
Own Kudos:
722
 [2]
Given Kudos: 240
Status:Under the Square and Compass
Location: India
WE:Marketing (Internet and New Media)
Products:
Posts: 691
Kudos: 722
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
samriddhi1234
Hi Bunuel

Please let me know if my reasoning is valid or if I'm going wrong anywhere, because I'm getting the correct answer.

As there are 5 tasks, we can arrange them in 5 x 1 (assuming 1st one is guest list so this task needs to be send invites) x 3 x 2 x 1 = 30 ways. and then the first two tasks can be arranged in 2! ways, so 30 x 2 = 60 ways. Is this also correct?

Appreciate the help!
Imo this approach is flawed, coincidently getting you the right answer -

1. Fixing "guest list" as the 1st task isn’t required, it can be 2nd, 3rd, etc., as long as it comes before "send invites"

2. If "guest list" is first task, it isn't necessary that "send invites" must be the second task, it can come at any time after fixing guest list

3. Multiplying by 2! does not seem to make sense to me

The key principle here is to understand that for exactly half the cases "guest list" will come before "send invites" => 5!/2 = 60
Moderators:
Math Expert
102569 posts
PS Forum Moderator
691 posts