Answer:
[tex]\huge \boxed{\mathrm{500 \ miles}}[/tex]
Step-by-step explanation:
A right triangle is formed.
300 miles and 400 miles are the legs of the triangle.
We can apply Pythagorean theorem.
[tex]c=\sqrt{300^2 +400^2 }[/tex]
[tex]c=\sqrt{90000 +160000}[/tex]
[tex]c=\sqrt{250000}[/tex]
[tex]c=500[/tex]
