What is the least number n with the property that, in every group of n people, there are at least three people who are all friends

hello your question is incomplete attached below is a the complete question

answer : n = 5

Step-by-step explanation:

lets consider N to be 5

To prove that the least number 'n' = 5

we will represent this information in a graph as vertex

Black edge = Friends

Blue edge = not Friends

From the attached diagram any  vertex contains 0,1,2,3,4 black lines and 4,3,2,1,0 blue lines

attached below is an explanation related to the choice of n = 5

considering n = 5 is satisfied by the explanation given