Answer:
The actual cities are 40 miles apart.
[tex]40\text{ miles}[/tex]Explanation:
Given that the distance between two cities on a map is 4 inches.
And the scale is;
[tex]1\text{inch : 10 miles}[/tex]It means that 1 inch on the map represent 10 miles on the actual length.
So for 4 inches on the map, the actual length will be;
[tex]\begin{gathered} 4\times10\text{ miles} \\ =40\text{ miles} \end{gathered}[/tex]Therefore, the actual cities are 40 miles apart.
[tex]40\text{ miles}[/tex]