A boy begins to walk eastward along a street in front of his house and the graph of his displacement from home is shown in the following figure. His average speed for in the whole time interval is equal to

A boy begins to walk eastward along a street in front of his house and the graph of his displacement from home is shown in the following figure. His average speed for in the whole time interval is equal to

Question : A boy begins to walk eastward along a street in front of his house and the graph of his displacement from home is shown in the following figure. His average speed for in the whole time interval is equal to