Questions tagged [extremal-graph-theory]

Question: 30 people need to place a call to each other using their cellular phones (one call per each pair). A cellular phone company gets 1 $ for each call between two people at distance between 800 and 1000 meters. The company is allowed to locate…

Consider the space $S$ defined by $S:=\{ (x,y) \mid 2x+y=2,~x,y \geq 0 \}$. Find the extreme points and the extreme direction of $S$. I found that there are two extreme points : $(1,0)$ and $(0,2)$. But I am stuck for the extreme directions, I…