Final answer:
The distance between the two cities on the map with a scale of 1:300000 is 3 cm.
Step-by-step explanation:
To find the distance between the two cities on the map with a scale of 1:300000, we can use the concept of ratios. The ratio of the distance on the first map to the actual distance is the same as the ratio of the distance on the second map to the actual distance. In this case, the distance on the first map is 12 cm and the scale is 1:100000, so the actual distance is 12 cm x 100000 = 1200000 cm. Now, to find the distance on the second map, we can set up the ratio:
12 cm / 1200000 cm = x cm / 300000 cm
Cross multiplying, we get:
x cm = 12 cm x 300000 cm / 1200000 cm
Simplifying, we get:
x cm = 3 cm
Therefore, the distance between the two cities on the map with a scale of 1:300000 is 3 cm.