Answer: 1442 miles.
Step-by-step explanation:
Given : The distance between Philadelphia and Salt Lake City = 2,147 miles
⇒ Round-trip distances between Philadelphia and Salt Lake City
\(=2\times2147=4294\text{ miles}\)
The distance between Philadelphia and Portland = 2,868 miles
⇒ Round-trip distances between Philadelphia and Portland
\(=2\times2868=5736\text{ miles}\)
Clearly, 5736 > 4294
Difference= 5736 - 4294=1442
[Note : We have no such need to estimate.]
Hence, the exact difference in the round-trip distances between Philadelphia and each of the other two cities = 1442 miles.
