Answer:
D. 96 miles
Explanation:
So, first, to get to the airport, we can take the shortest route, which is Elementary School to City Hall (21), then to High School (12), then to Airport (15).
This adds up to 48 miles.
Then, we go back to City Hall, through the High School, which is 27 miles (15+12)
Then, we go to the Elementary School from City Hall, which is 21 miles.
Add up all the miles and you get:
48 + 27 +21 = 96