Scale : 1 inch = 30 miles
So, the ratio between the distance on the map and the real distance is 1:30
When a quantity increase/decrease in a ratio, the other one increase/decrease respectively.
Call the miles we have to go : x
1:30 = 4.5:x
(1x4.5):(30x4.5) = 4.5 : x
4.5 : 135 = 4.5 : x
So, x = 135 => We have to go 135 miles to get to the place we want to go.
