Adog travels north for 18 meters, east for 8 meters, south for 27 meters and then west for 8 meters. what is the distance the dog traveled and what is the displacement of the dog.

I'm really not sure if this is right but I'll try.
The distance that the dog traveled is probably all of the distances added up. I would guess that it's 67 meters in total. 
The displacement is a little more tricky but you pretty much have to put a mental map in your head. Since East and West are both 8 meters, they cancel each other out. He travels more southern and that means the displacement is 9 meters south of his original location

On the galapagos islands charles studied finches