Answer:
0 miles, because the student is back at the starting point
Step-by-step explanation:
Displacement is defined as the change in the position of the object during its whole journey
So it is the shortest distance between initial and final position
Also we can say that it is the straight line joining the initial and final position of the object
Here we know that student leave from home towards a concert by a way which is 5 miles away
Now he returns back to home by longer path which is 7 miles
But here we know that initial and final position is same as he reached back to home
So displacement must be ZERO