Final answer:
To find out how far apart City C and City D are on the map, we use a scale from the given distances between two other cities. With a scale factor of 1 inch representing 200 miles, City C and City D, which are 3600 miles apart, would be represented as 18 inches apart on the map.
Step-by-step explanation:
The question requires us to determine how far apart City C and City D are on the same map, given the actual distance between City A and City B and their distance on the map.
We can solve this problem by setting up a proportion because the scale of the map is consistent.
Ratio for City A to City B: 3000 miles = 15 inches
This gives us a scale factor of 1 inch = 200 miles (3000 miles ÷ 15 inches).
Now, we apply this scale factor to the actual distance between City C and City D:
Finding the map distance for City C to City D: 3600 miles x (1 inch / 200 miles) = 18 inches.
Therefore, City C and City D are 18 inches apart on the map.