n people know each a different piece of gossip.

They can phone each other and exchange all they know so that after the call the parties know anything that either of them knew before the call.

What is the smallest number of calls needed so that everyone knows everything and how is this number achieved?

(In reply to re: solution, some doubts by Hugo)

That's pretty convincing, Hugo.  I guess that it is less than 2n - 3, when n > 3

16 people could do it in 2*12 + 16/2 = 32, which is more than 29

Posted by Steve Herman on 2012-07-26 18:52:32