Solve this

[buck]

PROBLEM: What is the minimum number of people needed at a party to ensure that either 5 people know eachother (that is, among these 5 people all of them know eachother) or 5 people don't know eachother?

*NOTE: Also, a person cannot know him/herself--and furthermore, we assume no prior knowledge as to how many people a person knows going into the party other than what we can deduce, or induce, by logical means.

Its no use googleing it, the answer will not be on the net...Why? Because it has not been solved since its creation, in the 1920s..

[Milenko]

I'm too tired for this.

[Fallout]

"If you you host a party, what is the minimum number of guests to ensure that either there is a group of n people that know each other OR that there is a grouping of n people that do not know each other" For n=3 the answer is that you need 6 people and for n=4 the answer (I think!) is either 17 or 18 (I am in the process of checking this out with Dr D R Woodall in the School of Mathematics who is a combinatorics specialist).

The aim of the project is NOT to do advanced combinatorics for n>4 but to investigate the case n=3 in detail,using the Internet Movies Database and its pairwise co-starring relationships. Then to provide a visually appealing and informative interface to show co-starring relationships of groupings of movie actors in dinner parties of size M. The case M=5 is particularly interesting: in most cases one can set up a "successful" dinner party i.e. one can find groupings of 3 mutual `friends' or 3 mutual `strangers', described above, but there is one "unsuccesful" case where you cannot (which is why M=6 is the minimum to guarantee success). (Note: we define whether actors "know each other" at these dinner parties not in the usual social way, but solely on whether they have co-starred in movies)

[Alex]

the minimum number is 6 lol

[Vendetta]

Without assumptions it cant be solved as there is no way to know who knows who.....ever. WITH assumptions, the answer is, as stated by fallen. 6.

[Fear Of The Duck]

PROBLEM: What is the minimum number of people needed at a party to ensure that either 5 people know eachother (that is, among these 5 people all of them know eachother) or 5 people don't know eachother?

i'd say 5

[Spacey]

I say 6 to know each other, and five to not.

I cite the "Six degrees of seperation"
http://en.wikipedia.org/wiki/Six_degrees_of_separation

[Grand Admiral Martin]

five

if i host a party i invite my 5 friends who are all friends.