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.