# Thread: Graphs theory, Trees and Paths

1. ## Graphs theory, Trees and Paths

(1) Let A={1,…,7} and let Rc=AxA be a relation which is symmetric and transitive. Youhave been given some partial information about the relation which is that thefollowing are known to be true for the relation:R(3,4), R(2,4), R(6,3), R(3,5), R(2,7)Using what you know about R show why it must be true that R(5,7) holds.

I was able to draw the graph but i cant find why (5,7) holds. I fould these (3,4) (2,4) (6,3) (3,5) (2,7) (4,3) (4,2) (3,6) (5,3) (7,2) (2,3) (2,6) (4,6) (6,5) (3,5) (6,2) (6,4) (5,6) by since the graph is symmetric and transitive but i cant find why (5,7) holds

edit: never mind found it