1. The problem statement, all variables and given/known data The problem is as follows; A boy begins to walk eastward along a street infront of his house and the graph of his displacement from the house is shown in the figure. His average speed for the whole time interval is equal to? https://scontent.fdel3-1.fna.fbcdn.net/v/t31.0-8/fr/cp0/e15/q65/17311005_704452213062233_4909110252429640342_o.jpg?efg=eyJpIjoidCJ9&oh=1c9f0cc2b2f56cd9f19c2586e956db44&oe=59697593 [Broken] 2. Relevant equations Average speed = total distance / total time 3. The attempt at a solution First of all, I'm confused about how to find speed from a displacement time graph. It should be rather distance time graph. Even if I find the total distance travelled by the boy from displacement graph and divide it by the total time , my answer doesn't match that given in the book. Here's what I tried : First I found the total distance travelled by the boy , which came out be 120 m , then divided it by 20 seconds. the answer I got was 6 m/s. But in the book , the answer is 2 m/s. I'm confused. even if I find velocity , which is displacement over time , it'll come out to be 0 , as total displacement is 0. Please rectify me if I'm wrong somewhere.