Answer:
15 miles
Step-by-step explanation:
You want to know the distance represented by 3/4 inch on a map with a scale of 1 inch = 20 miles.
Proportion
The idea of the map scale is that it tells you the proportion between map distance and ground distance:
map : actual = 1 in : 20 miles
We can maintain this relationship if we multiply each of its parts by 3/4:
(3/4)(1 in) : (3/4)(20 miles)
3/4 in : 15 miles . . . . . . . . . . . simplify
The actual distance Karen will travel is 15 miles.
