Answer:
1.25 miles or 5/4 miles or 1 1/4 miles
Explanation:
We just need to add the distance from the school to susan's house and susan's house to his house.
1/3+11/12=x
Make common denominators: 4/12+11/12=x
Combine: 15/12=x
Simplify: 5/4=x
x=5/4
5/4 miles