Answer: 6 miles will be saved.
Step-by-step explanation:
The total distance that he traveled is: 8 miles + 7 miles =15 miles to north.
And 5 miles + 3 miles = 8 miles to east.
Then the total distance is 15 miles + 8miles = 23 miles
If they did the direct path, the hipotenuse of a triangle with sides of 15miles and 8 miles, the distance would be:
D = √(15^2 + 8^2) = 17 miles
And the difference is equal to 23 miles - 17 miles = 6 miles
So they will save 6 miles if they use a direct path.