So, doing a guess and check,
Liza's house.
From Liza's house to the Park it is 5\(\frac{1}{2}\) miles.
From the Park to the Library it is also 5\(\frac{1}{2}\) miles.
From the Library to Dan it is 4 miles.
From Dan it is 3 miles back to Liza's house.
So you must add all those together,
5\(\frac{1}{2}\)+5\(\frac{1}{2}\)+4+3
We got lucky because 5\(\frac{1}{2}\)+5\(\frac{1}{2}\) have common denominators.
So,
5\(\frac{1}{2}\)
+
5\(\frac{1}{2}\)
=11 (\(\frac{1}{2}\)+\(\frac{1}{2}\)=1, so 5+5+1)
So that is 11, then,
11+4+3=18
18 miles total.
This is your route. From Liza's house to the Park, then Library, then Dan's, then back to Liza's house.