Question

The distance between two cities on a map is 18 cm. What is the actual distance between the cities if the map is drawn at a scale of 1:500,000?

Answer 1

18 cm = 0.18 m.
Actual distance = 500,000*0.18 m =90,000 m = 90 km.

(actually someone's earlier answer of 9000000 would have been acceptable if units in cm were included)