the library, post office, and gas station are all on elm street. the library is three miles west of the post office. the gas station is six miles east of the post office. how far apart are the library and gas station?

distance apart = 9 miles

Step-by-step explanation:

The library, post office and gas station are all on elm street. The library is 3 miles away westward of the post office. The gas station is also 6 miles east of the post office. The distance between the library and the gas station can be computed below.

The post office is located at the middle between the library and the gas station. The library goes 3 miles westward of the post office while the gas station goes 6 miles eastward of the post office. The distance apart between the library and the gas station is the sum of the distance of the gas station from the post office and the distance of the library from the post office.

Therefore,

6miles + 3 miles = 9 miles