1 mi 0.25mi
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A B C D
Let A be your home, and D be your friend's home.
You travel from A to C, which is half way from A
to D. Then you turn around and go back to B,
which is 0.25 mi. Then you go back to A which is
another 1 mile to get your book. So it's 1.25 miles
from A to C, and therefore twice that from A to D,
or 2.5 miles.
Answer: 2.5 miles.
Edwin