Answer: 5/8 miles
Explanation:
1. Add the distance from home to school, and from school to post office (7/8+5/6 = 41/24)
2. Figure out how many miles the trip was in total, given that she can travel a mile in 18 minutes and the trip was 42 minutes, by dividing 42/18, which equals
. The trip was
miles long.
3. Now, given that she has already traveled 41/24 miles from her home to the post office, subtract 41/24 from
. This equals 5/8, meaning that she traveled 5/8 miles from Post office to her friend's home.