Answer:
I guess you want to have an analysis of the graph.
Ok, in the first part, you can see how at the beginning the pilot is far away from the home airport, as time passes, he gets closer and closer (the distance gets smaller).
Then we get to the second part of the graph, we can see that the distance remains constant for a lapse of time, this means that the position of the pilot is not changing (so the pilot may be resting in a given airport), so he the distance between him and the home airport does not change.
Then we get to the third part, we can see movement again, he starts at the position where he was resting and finishes the travel at the home airport (when the line of the graph meets the x-axis means that the distance is 0, so at this point, he is at the home airport)
= 
= 7/4